So what happens when you pick up a hot girl in the M3? Take her to your parents house?
You're 22. Why anchor yourself with a car? Take your youth and money and travel, see interesting places and have as much sex with different girls as you can. You can always buy an M3 later, when you need it.
F82 M4 Individual / F87 M2 (on the list) / E36 M3 (track) / E21 320i (S52 + Getrag 420G Swap) / Fiat 500 (daily)