These are my stereotypes. They are stereotypes, but most stereotypes do have some truth to them, so don't completely write them off.
People who buy Hummers like to think that they're really bad-ass people who like to think they're as intimidating and as important as they're cars. They like to dream big, but don't ever live out their dreams. H1s are respectable in my book, but not H2s or H3s.
People who buy Mercedes cars like to think that they're very sophisticated and rich, even if they've borrowed far too much money to buy or lease the car. I also imagine Mercedes drivers as being older people with more car for their image than the car they drive. BMWs are more driver-oriented cars, in my opinion.