The BMW and a Rosary

Last evening my wife, a female friend, and I were driving down Charles St. from the beltway when a BMW convertible went whipping by us. The guy driving pulled into the left lane where we were and stopped at the traffic light, we were directly behind him. Hanging from the rearview mirror on the Beemer was what looked like a glass bead necklace. Then we spotted a cross dangling on the end and sure enough it was a Rosary. We were saying, what the hell is that there for! Our friend quipped that the Rosary was a trophy for screwing a Nun. We couldn't stop laughing for the next 5 minutes as the BMW sped away. Anyway it was funny at the time.