Pretty much every woman I know sees a flashy car and thinks "over-compensating jackass."
I do think that, as with that which can be overcompensated for, some men's self-obsession creates an illusion for them about women being just as obsessed. If you drive a flashy car, it will turn off women who hate that, be neutral to women who don't care, and attract women who love flashy cars--which will certainly make it easier to spot women who love flashy cars.
Similarly, regardless of what they actually drive, a lot of the kind of men who love flashy cars also like a very specific type of (flashy!) woman, and barely acknowledge that the broader spectrum of women exist--so if that small group of women is into (or is expected to be into, ahem ahem) flashy cars, then, obviously, women are into flashy cars. What do you mean all those women over there who aren't Barbie dolls don't care? They don't matter! Those aren't dating prospects!
(Anyway, as a lesbian, I don't exactly have a dog in this fight. Bring on the cute girls in their used hybrid hatchbacks.)