My dad has a story about mixing up cars that could potentially have been embarrassing (but luckily wasn't). My parents have both a Ford Explorer and a Ford Windstar. One day my dad was leaving a grocery store and went to put some stuff in the back of his Explorer in the parking lot. When he opened the back, he realized he didn't recognize the stuff that was in there. He had opened someone else's Explorer! But his key had opened it - he was confused. He inspected the key more closely and realized that he had used the key to the Windstar, and it had opened this other Explorer! Crazy.