door prize
n.— «I was knocked from my bike. My front wheel and shocks were damaged, but i wasn’t. The second time was a door prize. As i rode north up Yonge, someone opened the door of their parked car directly into my path.» —“A Coder in Courierland” by transient0 in Toronto, Can. Kuro5hin Mar. 19, 2005. (source: Double-Tongued Dictionary)