Development of World Car: 2009 Audi TT

There is only one Audi TT RS in the entire United States right now. And here we are, hurling the black coupe down the front straight at Willow Springs Raceway at 132 mph. We've been invited out to the sunny California desert on a pristine day to flog the hottest-ever Audi TT back-to-back against its TTS sibling, along with a few stints in the all-new S4 and R8 V10 for good measure.