29. Compact cars. They are bound to have been test-driven by a homer, who left his AIDS germs all over the driver's seat and steering wheel. Also, when other homers see you driving it, they will be seized with desire and try to molest you. Why do you think God gave us Hummers?
30. Cars with manual transmissions. They are also bound to have been test-driven by a homer, who used the shift knob for ... um, never mind.