*Rampant Unsupported Profiling Alert*

Bad:

Minivans (all kinds). Men who drive them overcompensate for the fact that buying the damned thing was the wife's idea, and he couldn't have the Mustang he wanted; women who drive them seem to be in a constant state of low-grade panic, likely because they're late for daycare/soccer/hockey/karate/piano/school/ballet/whatever (hi, sis!).

Boiracers. There's nothing like the Pwissssss! of a turbo system dumping pressure to say, "I (or more likely, my parents) have more money than brains." C'mon, an aftermarket turbo on a Dodgey Neon?

Lift kits. For men, the distance the truck has been lifted is directly proportional to the insecurity the driver feels over the length of his penis. For women, it's directly proportional to the length of the penis she envies.

Token good:

Corvettes (all years). Plastic fantastic + 215 pounds of me through the windshield = closed casket funeral for the driver. That, or the dent I'd leave in the car will worsen the owner's mid-life crisis. Either way, Corvette drivers give me a wide berth.