I also have a little plastic animal on the dash board. Is that personalisng my car? Does that upset you aswell? (It's a hippo, but I don't think it is entirely relevant to the discussion)
there are more elegant ways of saying "look at me" without having to use something as tacky and as a car. it seems being a petrol head gives you the right to be completely devoid of taste.
cars aren't inherently tacky, but tying to use one as a status symbol is.