I bought mine new in 2003 but decided not to track it for several years after reading numerous owner reports that it was not much fun. The C5 RS6 is not only heavy but very front-heavy compared to the more balanced Beemer. I think the figures are something like 62% front / 38% rear for weight on the Audi, 50-50 (or close) for the BMW. Even though I almost flunked high school physics, I retained enough to know that the RS6's (im)balance will result in strong understeer on a track with tight turns. In addition owners said tires and brakes get toasted, at least in front.
For years I sought in vain for a track event with wider turns that would accommodate the RS6, and finally found it last December. That's when four American owners were among 150 cars driven at the first ever Audi driving school held at Daytona International Speedway in Florida. The longer turns and steep banking (31 degrees) on Daytona's tri-oval made all the difference. "Cruising" at 130-140 mph with little worry about turns (because they're so heavily banked) was thrilling, to say the least. Everyone except me had prior track experience in their RS6, and all three agreed Daytona was the best track they had experienced for the RS6. Registration just opened for the 2008 event, which this time is limited to 100 drivers and will be held December 12-14 at Daytona.
Still, there are caveats. For our school the Daytona track was set up with a small unbanked "road course" (tighter turns) in the infield. On that, the RS6 did not do so well, its front-heavy proportions causing the car to slide some once the track heated up. Also, based on prior owner posts, I beefed up my brakes by adding Pagid blue bads, stainless steel brake lines, brake fluid with higher temperature tolerance, and brake ducts from the VW Phaeton. I experienced no fade, no soft pedal, and brakes always worked well, even when hitting the pedal hard from triple digit speeds (although I didn't do that often). One owner who arrived with brakes that were purely stock missed two 25 minute track sessions while waiting for replacement pads.
Here's the link to writeups about last year's event:
http://rs6.com/forum/showthread.php?...hlight=daytona
Below is a link to registration for December of this year. Cost is $999 -- not cheap, but it's three days, and brake mods that worked for me are less costly than a new setup from MovIt or elsewhere. Weather permitting (and it was fine last year), thrills are all but guaranteed:
Application forms can be downloaded from the Ohio Valley Chapter web site at
http://ohio.audiclubna.org
(click on "events" tab and then click on the "events calendar for 2008" link and then scroll down to Daytona).