You know BMW is serious about improving efficiency when you hear they're equipping the M5 with a stop-start system. But what else have the bayerische wissenschaftlers been cooking up to improve efficiency? Auto Motor und Sport brings us up-to-date on the innovations unveiled by BMW at its unimaginatively named "Innovation Day 2008." One concept that's sure to have green chins wagging: solar roof panels designed to run the cars' electrical systems. BMW estimates a square meter of roofspace in northern European conditions could deliver 200 watts; more still if the entire roof's covered in photovoltaic cells. Solar panel could be used to reduce dependence on efficiency-sapping alternators for on-board systems, which could deliver small improvements to efficiency (0.3 fewer liters per 100km driven) or pre-heat the engine and fluids, improving inefficient cold start fuel consumption. Bimmer's boffins are also looking at generating electricity from excess engine heat. BMW claims that current thermodynamic generators from aerospace applications could deliver 200 watts of electricity today, with up to 1k watts available next Thursday (or so). The combination of thermodynamic generators, solar panels and engine pre-heating could yield a five percent increase in efficiency. We'll wait until we see a cost – benefit analysis, but the propeller people deserve credit where CAFE credit's due.

Autocar UK has the latest details and a rendering of Nissan's updated 370Z sports coupe. The pic reveals an gently evolved version of the current Nissan offering. The Z's proportions, curved roofline and vertical door handles remain virtually unchanged. Other than new LED headlights, you'd be hard-pressed to tell elder and younger Zs apart. From what we can tell, a better-handling shortened wheelbase is the only major cosmetic change. The new sports car's 3.7-liter V6 will make 326hp, up from the 309hp offered by the outgoing 3.5-liter mill. Autocar speculates that the Z's new powerplant will sing a slightly more grunty tune than the G37's engine, thanks to variable valve lift and timing. Expect six-speed manual and seven-speed paddle-equipped automatic transmissions, as well as a welcome diminution of interior and road noise. Autocar suggests a diesel version, but they're going to pull the other one (it has bells on it).

As body-on-frame SUV sales crater, a number of manufacturers are prepping a new generation of lighter, compact soft-roaders. One such cute ute is Audi's Q3, based on the A3 platform and closely related to VW's Tiguan. Motor Authority has a rendered preview, showing off styling cues from the recently debuted Cross Coupe concept. Expect Ingolstadt's standard 2.0-liter TFSI four-banger, the 3.0 diesel V6 or the 3.6 FSI V6 to motivate the three and five-door Q3s. With Toyota's Urban Cruiser, Ford's Kuga, Landies LRX and BMW's X1 all coming online soon, the Q3 will have plenty of competition when it debuts in July of 2009. An official concept will hit the Auto Show circuit sometime before this time next year. While a higher roofline should help alleviate the A3's cramped cabin, the sharply-falling rear C-pillar won't win any friends amongst those relegated to the Audi's backseats. Let's also hope Audi designers do something about the rendering's weird flank lines, which have a confused, Bangle-on-PCP feel– especially compared to the clean lines of the A3. 

Regular readers should know by now that Autoblog Green will say nice things about anything that it considers "green enough." But as chic as it may be at the moment, the "green at all costs" posture has its downsides, particularly when you end up saying that the demise of the Bajaj three-wheeler is "unfortunate." Then again, maybe there really is something to be said for third-world three wheelers, because now ABG is all thrilled about the prospect of another pedicab special, this time from Thai firm Tuk Tuk, hitting the US market. The Tuk Tuk is currently undergoing EPA and NHTSA testing to see if the mainstay of Bangkok's taxi industry is ready for U.S. sales. And yes, for those who must know, the two-stroke engine which gave the Tuk Tuk it's goofy name is staying in the developing world where it belongs, to be replaced for American duty by either a 200cc or 650cc liquid-cooled four-stroke. It will be offered in a variety of body styles, for passenger, cargo or truck duty. The three-wheeled oddity may even be offered with an LPG drivetrain, which is sure to have the eco-friendly ice cream vendors lined up around the block.

It ain't easy being a small independent sportscar maker. Just ask Spyker. The Dutch firm lost $110m and a Formula One team last year. While Lotus knows exactly what hard times look like, they reversed the curse by eschewing flashy F1 campaigns in favor of a profitable technical consultancy and contract manufacturing (including the Tesla Roadster). The Motor Authority reports that Spyker and Lotus are facing the future under the umbrella of a "Parts and Platform Commonality Agreement." Lotus will  source parts and assist in the design of forthcoming Spyker C8 Aileron and D12 Sports Utility. Spyker will… pay for it. The two firms have worked together in the past; Spyker considered buying Lotus back in the day. With a Lotus-fettled Spyker at the top end of the market, is there still room for a new Lotus Esprit? No.

Chrysler's finally seen the light. After years of building versions of everything they build to sell under every brand they sell, they've canceled the Chrysler version of the Dodge Journey CUV. Co-prez Jim Press stopped by the passive construction site to explain that "resources have been deployed to basically support" development of the small car to be manufactured by Nissan. "It's a segment we are not competing in now." (What was his first clue?) Bloomberg reports that this move means Chrysler will only be introducing three new models for the 2009 model year: the Journey, the Challenger and a redesigned Ram. That leaves Chrysler looking toward the magic year 2010, when they hope to have their new compact ready to go along with new versions of the Grand Cherokee and Durango (no mention of the Aspen, though) and a redesigned Charger and 300. Will it be a case of too little, too late? We'll have to wait a couple of years to find out — if Chrysler lasts that long.

Ferraristi are set to get down on their knees and pray as the Prancing Horse has finally released pictures of their new California, The front mid-engined machine will debut (a French word) at the next Paris Auto Show. The +2 convertible features a folding hardtop and seven-speed dual clutch transmission. The horny Fornie's 4.2-liter V8 engine will hurl the aluminum-bodied GT to 60 mph in less than four seconds. Carbon-ceramic brakes should retard said insanity at will. [ED: At least until the damn thing breaks.] The Kalifornia's F1-Trac traction control system "has been further enhanced to suit the typical driving conditions expected for this new GT." Valet parking stand? Climate-controlled garage? Maranello's madmen are promising more details in advance of the show, 'cause they really need to build-up some hype for this new car in order to fill-up the order book before production. Not. [Hat tip to PistonHeads for the lead]

The Detroit News, internationalists that they are, report that Renault/Nissan is entering into a joint venture with India's Bajaj motors to take on the ultra-cheap Tata Nano (a.k.a. the one lahk car). Bajaj will own fifty percent of the joint venture, with Renault and Nissan splitting the rest. Together, they'll build a new factory in Chakan, India, Starting in 2011, the facility should eventually bang-out some 400k entry-level rides per year, heading for both the Indian and Chinese new car markets. No details are available about the powertrain or standard equipment (wheels? side mirrors? doors?). Whether this sudden craze for inexpensive mass market motors becomes a cash cow or a money pit remains to be seen; the challenge represents one of Nissan/Renault's most ambitious international projects. Still, Renault found plenty of karma with their first forray at the bottom of the market with the [formerly Dacia] Logan. The Indian version, built with Mahindra and Mahindra was a big hit for all concerned. The Iranians also build a version, but that's a story for another day.

Autocar reports that British speed merchants McLaren are set to ulneash another of their own-branded supercars. The P11 ('cause an actual name would be way too mnemonic), the new whip is set to debut in 2010. Autocar is quick to point out that the P11 isn't designed to eclipse the previous gold standard (literally) in supercars: the BMW-powered, three-seat-abreast F1. The P11 will offer "just" 550 horsepower from its Mahle-sourced V8. To emphasize the P11's status as a driver's car– as opposed to whatever you'd call the Mercedes McLaren SLR AMG– the company will hang fire on the drop-top Spider version. (Explain?) A subsequent P12 should up the ante with a lighter chassis and a 600hp V10, which may or may not sound like a bag of bolts in a cement mixer at idle. Anyway, it looks like Macky's back in town. 

Automotive News [sub] reports that Hyundai/Kia have scrapped plans to build a mid-sized unibody pickup truck at their new plant in West Point, GA. Sources from Hyundai (PR department?) say the truck (thought to be inspired by Honda's not successful but we build it on the same production line as the Odyssey and Pilot so who really cares Ridgeline) would have been built on the updated 2010 Kia Sorento chassis, which is set to switch to unibody design. Instead, the Georgia plant will build a Kia small car, likely the Optima. Executives say a Hyundai-branded car may be built there as well, "if the platform is compatible." As consumers turn away from large body-on-frame trucks, you might have expected a yen for lighter, unibody trucks (just as VW's Rabbit-based pickup sold well during the 1970's fuel crisis). And you might be right. But Hyundai/Kia's not about to make that gamble. Not with so much riding on the (larger and heavier than typical for Hyundai) Genesis RWD vehicles. 

Big trucks have meant big profits for Detroit. Thanks to cheap oil, personal paranoia, a desire for an outdoor life that only the drudgery of daily commuting  could provide, the fairer sex' natural desire to see ten miles ahead at all times and a federal fuel economy regulation loophole big enough to drive an Expedition through, The Big 2.8 managed to convince Americans that body-on-frame vehicles were just dandy for personal transportation. With gas price increases showing no signs of slowing, one of Detroit's biggest truck chassis addicts is looking at kicking the habit. Bloomberg reports that GM, yes GM, is developing a lighter replacement for its biggest SUVs (Yukotahburbelade) that won't tow jack shit rely on a heavier pickup-truck frame. This, according to "people familiar with the effort." (Familiarity breeds PR.) It should be said (and soon will be) that GM has been relying on the same basic Silverado full-size truck platform its "light trucks" since 1965. Even if truck-framed transportation isn't about to disapper overnight, at least GM has taken the first steps to beating its addiction to "easy" profits. It has admitted it has a problem. 

Auto Motor und Sport's Erlkoenig spies have spotted Porsche's new Roxster baby ute being shaken down in camouflage. The fifth member of the Porsche model line is based on Audi's forthcoming Q5. There had been talk of the Roxster boasting a 400 hp version of the Cayenne V8, but carbon emissions rules have likely put that idea to bed. The same V6 slated for Ingostadt's iteration will likely power Porsche's cute ute (ugh). The styling appears to remain fairly faithful to the Cayenne's forgettable shape. Auto Motor und Sport thinks Porsche has attached bits of Cayenne to the Roxster test mule, but a shorter rear overhang and steep rear c-pillar give the Roxster a much more pert rear quarter than the billious Cayenne. Up front, the headlights appear more Cayman than the Cayenne. Look for the Roxster to debut in 2010 (our favorite year), sometime after the Panamera four-door GT becomes the fourth Porsche model line (counting the Cayman and Boxster as a single line). Clearly, BMW has to worry about X3 sales. But without a V8, will Porsche offer anything (besides a higher price and some brand snobbery) that the Audi doesn't? Let the spin begin!

GM is counting its unhatched Volt chickens while its battery system is still laying an egg by announcing a line of Volt-based Opel EVs which will hit Europe's roads in 2012… provided the Volt is actually ready by 2010. Auto Motor und Sport reports that the Volt's European launch should take place in 2011. The Opel EV will arrive a year later, using the same E-Flex drivetrain.  There will be two Opel models: a compact based on the Flexstream concept (pictured) shown at last year's Frankfurt Auto Show and a considerably larger sedan. Both vehicles will share the Volt's 40-mile EV range, as well as the small range-extending gas motor. Interestingly, GM also showed a Saturn version of the Opel Flexstream in Detroit, raising the possibility of a stateside bow for the badge-engineered Volt. Of course, if the all-important lithium ion battery development runs into problems, GM will be more than happy just to get a Volt out. Meanwhile, this announcement proves just how much is riding on GM's "moon shot." 

Autocar UK reveals the forthcoming high-performance sedans from BMW and Mercedes Benz. The new MB E63 AMG will be a "clean slate design," with only the monstrous 6.2-liter V8 returning from the current model. The uber-E's Nürburgring-tuned suspension– wider front track, a unique steering ratio and active damping (as well as a possible electronic rear differential– demonstrate AMG's newfound emphasis on handling. While the new E63 will share components from MB's C-class, don't expect the AMG derivative to come cheap though (as if). The UK price tag is over $100k. While Mercedes wrings-out its E63 at the 'Ring, BMW is busy developing its 2011 M5. The current M5 V10 engine will return, albeit bored out to 5.5 liters. Yes, but– "[the new M5] is also likely to get a direct injection, turbocharged unit, to reduce emissions. BMW is considering bringing stop-start technology and a part-time alternator (branded "regenerative braking") to the uber-5. But perhaps the best news: the Boyz from Bavaria are ditching the SMG, which RF dubbed "the world's worst gearbox." M5 fans will choose between a new six-speed manual gearbox or the new seven-speed M DCT double-clutch transmission. 

Forgeddabout that unstable idle. (We're pretty unstable when we're idle too. Alternatively, unstable idles are the devil's plaything.) The new Mercedes SLC looks to be what the Mercedes McLaren wasn't: affordable. Wait, that's not it. While I'm busy thinking of a witty repost, play the video and contemplate the joys of burning a gallon of gas every couple of miles with your tail wagging like a miniature Schnauzer that just eviscerated a large rat (no animals were harmed in the making of this metaphor). Pistonheads' passive construction workers [via Motor Authority; you know how that goes] tell us that the SLC "is likely to be a direct successor to the McLaren SLR and is expected to be fitted with an AMG 6.2-litre V8 producing almost 700bhp." But who's listening when that monster motors' mauling the tarmac? Never mind all that when did TTAC start promoting gas guzzling hypercars while criticizing gas-guzzling hypercars stuff. When did Mercedes decide it was OK to crib the font end design from a 1979 TVR 3000 S? And how the Hell do you get out of a gullwing supercar in a supermarket parking lot? [Frank: very carefully.]