Expensive cars get whores. A Ferrari, new Porsche, Audi R8, you name it will get you a gold-digger every time. It's why middle-aged men buy Corvettes (and that demographic is why Corvettes can be had with automatics). When she finds out you live in a shack and work 80 hours a week just to make the payment and insurance, you'll wonder what happened to her.
A cool car is an ice-breaker, even if it's crappy. I proved that with the Black Bitch more than once. One very-attractive woman loved it for the potential she saw in it, and we became friends though circumstances prevented our dating (she later regularly drove, and did her own service on, a CBR600RR). Another one whom I did date looked at the car and figured I had an, uh, "interesting attitude". Interesting enough that we dated for a few months.
A cool or offbeat car will get comments from women that will definitely open the door, but if you're a slack-jawed mouth-breather that can't carry the conversation beyond the car itself, you'll be dismissed in a hurry. So yeah, a car can get you the girl, but only if you were capable of getting the girl without the car in the first place.