I went to an M3 from my Evo X which had to be the biggest dick magnet this side of the GT-R and in comparison, it's been successful in this respect.
I get all kinds of compliments and looks from women, and even more wanting to go for rides. Hell, I met a chick at a pool party once who overheard these guys talking about "Oh that's the dude with the white M3?" ...15 minutes later I was taking pictures of this gorgeous girl on my car. ALL her idea.
Final Verdict: Both.