If you are already into your 328 for some $$ I would keep it. Go to some driving schools and enjoy the car. Then when the M3 is less in demand and the bugs are worked out you can pick one up slightly used or a second or third year version (with the bonus of a price at or below MSRP). Ask 1997 E39 owners how "bug free" their first year cars were. One guy just posted on the E39 board about how he dumped his problem-ridden '97, got a '00 and has had 0 problems.