I'm not sure how my demographic plays in, but I am more of an experimental buyer, meaning I have no loyalty to any brand, I just buy whatever feels good to me. I'm 30 now, here's a list of the cars I've owned since I was 15:
15-1/2 - First car was a brand new 1989 Dodge Daytona Shelby. For 4 months until I turned 16 I couldn't even drive it without my parents.

I paid for it though, not daddy's money.
18 - New 1991 Jeep Wrangler (base)
21 - Used Audi 4000S
23 - Inherited my grandparents 1987 Dodge 600
24 - Used '87 Audi 5000CS Turbo, used '86 Alfa Romeo GTV6
--- all of the above was during my "poor" days while I was still in school or just starting out ---
25 - New 1999 VW GTI 2.0 (finally started making real money in present career)
27 - New 2001 VW GTI VR6 (got a promotion that year)
28 - New 2002 Isuzu Axiom 4x4 (totalled my VR6, decided to punish myself with a SUV)
30 - New 2005 Dodge Magnum SXT (after gas hit $2/gal. time to get rid of the SUV)
Funny how in 15 years I have come back around to a Dodge. Never woulda thought.