It's a little difficult to stay focused on the subject matter of a press conference when an international pop star swans his way onto the stage. At its Detroit unveiling, Audi dropped Seal (yes, that Seal, and no, he didn't bring wife Heidi Klum with him) onto the dais, ostensibly because A) their products are getting "a little bit crazy," and B) Seal himself uses an Audi Q7 as his personal car. Personally, we stopped staring at the Audis and started staring at the dude getting a little too familiar with the microphone stand while singing his lungs out. But then, you probably would have too.

It's not as if the cars on Audi's stand weren't worth the attention; they were.

A 200-mph racing car, a nondescript family truckster, and a 500-hp sport-utility wearing absurdly large chrome wheels were stretched across almost fifty yards of glossy white floor tile.

The interesting part? They were all diesels.

Yes, that's right: 500 hp from a diesel engine - and it's bolted into an Audi Q7. (photos from automobilemag.com) Two hundred miles per hour from a 650-hp diesel racing car, and it's quiet enough that, while cornering, all you hear is the odd tire chirp. And an ordinary sport-utility that burns diesel fuel without being slow, smelly, or boring to drive.

Audi's diesels represent a newfound focus for the brand, but it's one that backs up their long-spouted "Vorsprung durch Technik" (progress through technology) slogan. 2006 was a record year for Audi in terms of sales -- over 905,000 Audis were sold worldwide, a 9% increase from last year -- and it's the eleventh such year in a row for the Ingolstadt brand.

Success breeds branching out, and for Audi, "branching out" means "diesels." Audi's diesels are widely sold in the rest of the world (they account for 50% of all Audi sales), and are the epitome of modern diesel technology: quiet, fast, and fun. (They also offer twenty to twenty-five percent better fuel economy than their gasoline-engined counterparts.)

Audi's first diesel toe into U.S. waters will be the Q7 Bluetec TDI, powered by a 3.0-liter V-6. It generates 369 lb-ft of torque at a superlow 1750 rpm, and pumps out 233 bhp. The "Bluetec" bit -- a brand name for clean-burn diesel technology that's shared with some Mercedes-Benz vehicles -- will help ensure that the diesel Q7 will meet emissions requirements in all fifty U.S. states.

The 500-hp Q7 V-12 TDI concept? Although it's not earmarked for production, the concept features the world's first 2,000-bar Bosch Common Rail fuel injection system, hits 62 mph in just 5.5 seconds, and conforms to the Euro 5 emissions class that comes into effect in 2010. Fuel consumption is 20 mpg.