Red Spot

A truck driver breaks down and shortly another trucker stops to give him hand. He notices that the first driver has a big red spot painted on his dash and asks him what it's for.

He replies "Oh that's a conversation piece for when I pick up female hitchhikers. I get lots of action that way."

The other driver thinks that's a great idea so he paints a red spot on his dash too. Then he sees a girl hitchhiking so he picks her up. She notices the red spot on the dash and asks him what it's for. He says "It's a conversation piece. You wanna f*ck?"