Most people don't drive the car they want. They drive the car they need, or some compromise of the two. What people drive does not lend credit to their opinion, or detract from it. Not in my opinion anyway.
I've driven many American cars, and my favorite was my father's 1976 Trans-Am Firebird 400 ci, blown and nitroed to 600+ hp. Smoked the cops once in that car when I was 19 and immortal (read: stupid). Well, the cops drove a Volvo 245 so it didn't require much effort. The worst American car I've driven was my father's 1991 Ford Taurus station wagon (my father is an AmCar enthusiast you see). It was horrible, and after a couple of years the clear coat started flaking off so the car looked like it had a bad case of psoriasis. After that he turned to Mercedes for a few years, but his latest car is a Grand Voyager (Chrysler brand in Europe) which is an ok people mover, but again there are quality issues especially with the electrics.
I didn't buy the BMW because it was my dream car, but it was a nice compromise that I could afford at the time. My Isuzu pick-up truck certainly isn't my idea of a great car, but it get's the job done (the ones I don't want to put the Bimmer through).
Does that lend credit to my opinions? No. Nor does it detract from them. IMHO of course.