Well, maybe it IS wrong to generalise about someone just from the car they drive.... but then again its not as if you're given a car at random by the DVLA and locked into it's ownership. Both the new and particularly the used motor markets display a mind bogglingly vast array of styles.
Excepting cars being borrowed within or passed on through families (my own is a hotbed of this), there is a degree of choice involved on behalf of the driver. Without a certain limit on what you are or are not prepared to drive, or what features and style you want in your car, you could end up with any old sh*te, and i'm sure that's not actually the case for most people. For my brother it is true - his car is one my neighbour came into when a lifelong friend of his passed away, and had to get rid of
somehow. Too bad it's an image-free, faded-red, 80s style astra, and that his will didn't mention that the fuel lines were shot.. Still, bro dont care. It was a super cheap motor, and it gets him back and forth. To judge him from it you'd say he's someone's grandad or great uncle, which certainly aint true, he just doesnt express himself through his car.
For me, partially so, partially not. If I was completely without regard for all that, I would have started my self-owned driving career in a 900cc Nova or Corsa almost for sure - no cheaper way of going about it! But their safety was suspect, and I didn't fancy the wideboy/estate-scum connotations. Sooner a skoda estate than that (quick, roomy yet compact, economical, and hell-ass quirky!), which is possibly why i ended up plumping for the polo

(and pure practicality, with the ashtray)
Even on top of all that, I doubt even my bro wouldn't have some twinge of a second thought at owning - rather than, say, borrowing - a New Bug. It is so, so a girly car, far more than even a Ka is (or a StreetKa.. just), and even if just because of the massive waste of potential interior room with all the dysfunctional retro plastic and body panelling all over the place, he'd go off and have a quick gander through the autotrader in case someone saw him out in it.
An image-free, boring old banger is one thing... something a bit newer, that you must have dropped a four or five figure sum on, explicitly designed with what - for you - may well be a negative image is an entirely different matter.