We recently had the opportunity to test an '09 A6 convertible on a chassis dyno.
The results were impressive--376.51 rwhp and 371.52 rwtq, or around 443 and 437, respectively, at the crank. While we didn't have a chance to run the car at the track, the Victory Red droptop likely would have been good for mid 12s at 113-114 mph.