IMO men buy cars to impress women, because your average woman is impressed.
See I don't agree with that I; think a plurality of average women are impressed (probably because they're conditioned to be impressed) and that gets really exaggerated. The reason I think this gets so blown up is it gives a concrete thing to latch onto that's easy to understand and relatively easy to imitate.
Lals....well, yes, it IS a concrete thing that both men and women can latch on to.
Biological explanation follows, based on the following:
Did anyone see "The Human Animal", a BBC Documentary?
http://en.wikipedia.org/wiki/The_Human_Animal_%28TV_series%29Gist:
Biologically driven Female breeding strategy for success is to insure her offspring are fathered by strong male genes. Male must also be a good provider, since the maximum number of times a female may potentially breed in her life is less than 50 (considering maturity, gestation time and subsequent menopause - assuming no chemical induced multiple births). Therefore, the father of each offspring must be carefully chosen and the child provided with sufficient resources to be able to grow to maturity and breed itself, thereby passing on the genes successfully. A male that is a good provider increases resources available to the child, increasing the odds of survival versus a lesser provider, or an absent one. Side note: In this strategy is the explanation for female infidelity - the one with the best genes for breeding offspring is not necessarily the one who is the best provider of resources to insure the offspring survives. This brings up the potential to partner with a good provider, but secretly have children with another who has better genetic material for breeding.
http://en.wikipedia.org/wiki/Misattributed_paternity (0.8%-30%, median 3.7%).
Biologically driven Male breeding strategy for success is totally different that the female strategy. The short version - sow your seed far and wide knowing that the progeny that results will be that of a female who has limited opportunities for breeding, hence will put the effort into raising her (and your) offspring to maturity and to breed itself, thereby passing on the genes. Even if you run out on her, if you father enough children, some will make it to adulthood and breed themselves. Potential number of times a male may father a child? Lets see...thousands? This is the (duh!) explanation for male infidelity and the typical desire for dirtbags to trade in Wife 1.0 for the younger Girlfriend 2.0 (and 3.0, and 4.0).
So, what the hell does this have to do with males and cars and "what women thing of males and their cars".....
Having a fancy, expensive car for a (typical) male is a demonstration that a certain level of resources are available (or used to be, before the advent of widespread, easy to get credit). The (typical) female notes that said demonstration of resources indicates that said male may be a good provider of resources - one of the factors that will increase the probability for her successful breeding. The biological imperative for a female is to want resources to insure the success of her breeding, hence the natural attraction to males that demonstrate the ability to provide said resources. In other cultures or other times, the demonstration of resources would have been different - a big herd of cattle, a well stocked granary, pale skin and a bit of fat on the belly (yes - in some cultures, being pale and fat was good "In times past, when most workers did physical labor outdoors under the sun and often had little food, being pale and fat was a status symbol, indicating wealth and prosperity (through having more than enough food and not having to do manual labor).
http://en.wikipedia.org/wiki/Status_symbolNote: The above explanation from the noted program is a biological / zoological explanation of why (some) women are impressed with (some) men who have fancy cars, and is a hypothesis of why these certain behaviors are present. Of course, it doesn't take into account modern social or culture norms nor rational thinking, with which a person can choose to ignore the simplistic cues that biology may provide.
Note: I would imagine with the ladies and gentlemen here on the MMM forums, a flashy car would rightly be a demonstration of wastefulness of resources.
Personal note: I drive a used Toyota Corolla. I've never been into flashing status symbols and have never done that. I find the whole behavior complex of status symbols (both males that do it and females that respond) to be juvenile.