Your wife decides to go out with her friends drinking and dancing.
(E'hem Night)
You're okay with it, because you get to watch sports all night
**edit** and play CS.
You hear her stumble into bed around 4.
You wake up next morning and go outside to the family Volvo, which
she used last night.
You are happy to see it all in one piece.
But ... Wait a minute ...(Look at the Volvo a
little closer)

Of course, if she stops at the car wash before she goes out...