Dunno if this has been mentioned yet
Hrm... How about a Prelude SH? You can find a 1999-2001 in the low teens, keep some of the driving and maintanence(I always misspell that word) characteristics you've grown used to, but you have an arguably more refined looking and feeling car...
Not an M3, but it's a good looking alternative...
***edit: Or how about a Volvo S40 or S60? If you're looking for a more mature and cheaper car, that is?