Originally Posted by footie
Actually you are wrong with this opinion that there is no ideal car for every track, a few spring to mind. The GT2, GT3RS, Caterham R500, the F430SC and the R8 but to name a few.
On any track weight is the key to producing a car which is both capable of a tight track as well as a long and flowing one. This is why the M6 will have problems on anything other than a track with long straights and fast flowing corners. Currently there is only two M cars in production which is suited to track work and they are the new M3 and the Z4M coupe, all others are to compromised for anything other than a bit of fun.
Actually weight is one of many variables. Others may include weight distribution, power etc and most importantly tires.
Every track is different and no car is best for all. Every car is a compromise.
I will take my M6 against your RS4 / S5 anyday of the week on any track that doesn't involve snow.