Tell your parents to keep their money. Use your own, hard-earned money and buy an S2K. Your parents will respect you, you'll be respecting your parents, and you'll appreciate a car that you didn't buy with daddy's money.

Also, please tell us that you're not moving back home after you graduate.

 

Given the choice I'd definitely take the M3. But there's also something to be said for buying a car without help. I guess it all depends on your relationship with your parents.

How's this: get the S2k and invest the extra money from your parents. After a year or two, if you want to get an M3, sell the stook and do it. Or if you want to keep the stook, then you're golden also.

 

HAD a 430hp Audi S4 that was plenty fast, but it did not stir up the pure driving emotion that the S2K does. The M3 is the same way, too isolated from the driving expirence IMO. I wanted a car that made ALL of my senses feel as though I were driving an F1 car, IE I was not just looking for power, but the whole package. The M3 and S4 are awesome cars, but if given the choice I would still go with the S2K as I have done, unless you plan on having any passengers, then go with the S4, because getting a TON of extra power out of it is easy. BTW both of these cars are heavy and handle that way even with coilovers on my S4 the S2K is still more fun, not to mention you can get the power to weight ratio up on the S2K and beat the hell out of both of these cars (here come the flames, I can feel it)
My .02

 

It is difficult when you're young because you don't have much patience and you want everything NOW!, but I would put an appreciating home with a garage on the list before any depreciating vehicle - but if it must be a car and your only car, get the one with 2 back seats and a larger trunk first.