Audi S6 - 3:09.8
Here is cruel proof of what a track can do to an otherwise estimable sports sedan. Fresh out of the box, the new S6 bested the Mercedes-Benz E63 AMG and the BMW M5 in a comparison test. Then we sent this example, as white as coconut meat and freshly shod with new tires, out on VIR's evil asphalt. The result was a wince-inducing horror show of understeer and lap times that didn't come close to the M5's.

Because all-wheel-drivers tend to understeer, a certain iron fist is often required to hustle them around a track. It's best to storm up to a corner, hit the brakes hard, jump off the brakes abruptly to tease the car into rotating, and then stomp on the gas in the hope it'll provoke the rear axle to do something useful. But the Audi, even fitted with a torque-vectoring rear differential, proved immune to our cattle-prodding. We also tried to be gentle, but the S6 just wouldn't bite. It took achingly long to get through the slower turns as the front tires squealed their arias of woe. And at 4,369 pounds, the S6 could only make it to 136 mph on the straight.

Once straightened out, the twin-turbo V-8 quickly boiled up its steam and the S6 left a thrilling, big-bore sound in its wake. The dual-clutch transmission makes up in lightning shifts and downshifting throttle blips what the rest of the chassis lacks in track aptitude. In our estimation, however, the Audi leaves the event as it entered - as the market's best big, fast, luxury car - even if it's a machine that can't be what it wasn't intended to be.