I recently sold my 2010 M3 for a GT500 and stock for stock that guy would have to be crazy to think he had a chance. No competition there. I had an ESS 625 blower for about my last year of ownership and that would make it close from a roll, but I think my nearly stock (for about another week) GT500 would still take it.
The E92 M3 is a great car, no doubt, but serves an entirely different purpose than the GT500.
On a side note, I was a long time, contributing member of an M3 forum and the responses I got upon trading the M in on a Shelby were absolutely ridiculous. In my experience, most M3 owners really are not true car enthusiasts and have no appreciation for anything else. Most also wouldn't know how to change a tire or even a headlight bulb. You guys would laugh your asses off if you saw all the threads posted on the most basic of maintenance questions.
Well I disagree with part of this post because anybody who has spent any time on the M3 forum know they definitely have appreciation for other cars, in fact they are trying to get the name changed to P car forums lol