Beyond windswept hair, here's another good reason to not drive a convertible -- things tend to fly out, like money.

Reuters is reporting that a man lost 23,000 euros, or $31,180, when an envelope with money he had stuck in the passenger seat pocket of his convertible blew away during a test drive in northern Germany.

Luckily for him, police blocked the motorway in both directions for nearly 30 minutes, and eight officers helped him collect most of the cash that was in 500, 200 and 100 euro notes. They recovered 20,000 euros, or almost all of the money that blew out of his car.

The final 3,000 euros haven't been found, and police are warning people searching for the lost bills that keeping them is illegal.