2 different type of vehicles in my opinion.
M3 better overall
Vette, easier to modify to go fast, and also cheaper to do so.
the vette is much harder to drive on a track, straight or with curves.
much more difficult to launch.
edge goes to M3 in 1/4 and 0-60, unless the vette driver knows his car very well.
but if have a lot of seat time with the vette, it should win.