There's a sticker in the new BMW 5-Series that tells you everything you need to know about the mid-sized motorcar. This permanent post-it, affixed just beneath the infamous iDrive controller, has a tiny arrow pointing left and the words "Climate, Air Dist. and Vent Temp".

Before iDrive, BMW drivers adjusted the vent temperature with a small wheel between the vents. This easy-to-use function was originally created and sold as a safety feature; cold air on a driver's face aids alertness. With the new 5-Series, not only do you have to be computer literate to cool your fevered brow, but you have to take your eyes off the road to do it.

First, you push the iDrive controller down to release BMW from corporate liability. Then you nudge the controller left to select "Climate". A hieroglyphic appears. Twist the knob for the correct function, press it, twist it, look up to avoid oncoming traffic, look down, press the iDrive mouse again and… I think I've made my point. Which is simply this: BMW's new 5-Series is a deeply conflicted automobile. It still aspires to be "the ultimate driving machine", but it no longer knows how.

There are signs of struggle are obvious from first glance. Much has been said about the strange "bustle" protruding from the 5's trunk lid. But focusing on this jarring detail ignores the wider conflict. Designer Chris Bangle has tried to graft sporting intent onto a deeply conservative, highly evolved shape. It doesn't work. His "flame surfacing" (a pretentious phrase for a wild amalgamation of swage lines, creases and indentations) is the art student's equivalent of a tuner's macho side skirts and spoilers.

Sure, the 5-Series now looks aggressive and interesting, but it doesn't look right. There's simply too much going on, too much needless affectation, from the car's curiously feline headlights to its bulbous bum. Bangle's quest for sporting modernity is neither true to the brand nor attractive in and of itself. As strange as it sounds, the new Acura TL, a 5-Series knock off, does it better.

I would love to say that the car's driving dynamics make up for these deficiencies. Unfortunately, the test car came with Dunlop SP Sport 01 DSST tires and BMW's new-style variable-assist power steering. The former are 18" run-flat tires while the latter electronically alters the steering ratio according to your speed. The combination produced such vicious tram lining I thought the tires were worn out. They weren't, but I was, fighting a never-ending battle to keep the car pointed in a straight line.

I realize the gravity of that statement. Accusing a BMW sports sedan of darting around like a skittish horse is like calling a Rolls Royce cheap and cheerful. So I stopped by my local BMW dealer to test drive a 530i with "normal" steering and tires. The bread-and-butter alternative offered suitably meaty steering feel and perfect straight line stability. Great, but since when does BMW sell a sports package that degrades the base model's ride and handling? About the same time they decided to sell a car with a manual gearbox that's both rubbery and notchy. BMW claims the 530i's six-speed has a "precise athletic feel". Sure, and championship wrestling is "superb athletic competition".

Don't get me wrong. Somewhere underneath this farrago is one Hell of an automobile. The 530i Sport corners with minimal body roll and exemplary poise. Its 225hp powerplant is a bit sluggish at low revs, but once it crests 2500rpms the double-VANOS system kicks in and away you go. The silky smooth in-line six has enough grunt to propel the 3461 lbs. mid-size sedan to 60mph in a fraction under seven seconds whilst achieve 30 highway miles per (US) gallon of dead dinosaur (credit the overdrive sixth gear).

I have no doubt that the 530i Sport would offer something akin to a rewarding driving experience if it came equipped with some proper sports tires, an automatic gearbox and standard-issue rack-and-pinion steering. Of course, that would still leave the stupefying iDrive and flame-broiled design. And the fact that the switch that raises and lowers the rear window shade is now on the driver's door, while the central door lock button has moved to the center of the dash. Amongst other things. Anyway, you may have guessed by now that I'm not a great fan of the new 5-Series. Still, I'm willing to re-consider my position once Bimmer's bad boy M-division lowers a 500hp V10 into the 5's engine bay. As any muscle car owner will tell you, massive acceleration can cover a multitude of sins. Even then, I'll still be worrying about this brand.

Unless and until the Boys from Bavaria get back to basics, its future is in jeopardy. Creating understated cars that stay true to the company's driver-focused creed is BMW's ultimate challenge.