Getting head while the GIRL is driving the car. Though tricky, it can be accomplished by having her work the gas and brake while you control the steering wheel and she's humming on it. The unsafe feeling plus the sensation of a blowjob combine to take ecstacy to new heights.
"Man, I whipped my dick out while in the passenger seat and she started sucking it while she drove!!" - Me
"Wow that's unsafe." - Friend
"Nothing's better than the chance of death while you get drovehead." - Me