Lady Cab Driver by Prince

It's about "driving". It's catchy and so dirty it would make everyone else in the car incredibly uncomfortable, unless it's that kind of roadtrip.

Plus, Disneyland mention.

I spent my last $10.00 (on birth control and beer) by Two Nice Girls

Who says lesbians have no sense of humor? Excellent sing-a-long.

Brunhilde's Immolation Scene from Gotterdamerung by Wagner

At 19:56, this is the longest track in my iTunes library. Long stretches on the road are a great time to process difficult emotions. Contemplating the soprano-sacrifice of Brunnhilde as she self-immolates in order to remove the curse from the Ring of the Nibelung is an excellent path to introspection.