A Chevy engineer and a Ford engineer are in the restroom at the urinals. Ford engineer finishes first (natch, First On Race Day) and walks out of the bathroom.

Chevy engineer says "Aren't you going to wash your hands?"

Ford guy says no, and Chevy guy says "At Chevy they tell us to wash our hands after using the bathroom."

Ford guy says "At Ford they tell us not to piss on our hands" and walks out.