londoner2001 said:M3 wouldn't have a chance against an RS6, dude you sure it wasn't an S6 or Rs4 you came across? The M3 man would have to get his gear changes just right to be slightly behind the RS6, all the RS6 needs to do is get a half decent start then once foot's flat leave it there, it does sub 13 quarter mile as standard and has prodigious grip, nice car but bit big(Sure the CL drivers will laugh at that comment!).
I know my cars, it was a RS6. Also, if you look at the figures (for what they are worth) you will see little difference - 0-100 the RS6 is about 1/2 a second quicker (most would be from initial 4wd traction), and the only 30-70 time I could find for the RS6 was 4.6 secs (vs 3.9 for the M3). Also, gear changes weren't much of a problem - SMG gearboxes are great for making quick changes - not many manual drivers or auto gearboxes can change gear in 80ms....
I also probably should have mentioned that this wasn't from a standing start, therefore the off the line traction advantage of the RS6 was lost, and the greater weight was counting against it, and it also included 'a corner' which could have had something to do with it (and is why I found myself a bit sideways at one point!). Sense and traffic knocked it on the head by about 90, so no idea which was quicker at the top end.
Don't get me wrong - I like the RS6 - think they're great cars, and have considered one myself, but on this day, in this instance, my M3 was faster.