During the wedding reception, George (Steve Martin) is called outside to meet with the police because there are too many cars parked in the street. Notice that the police car is curbside completely surrounded by cars. In fact, the whole street is packed with cars, making one wonder how the police car got up to the house.
While Steve Martin and Nina are discussing the Wedding Coordinator, Martin says they will end up broke and walking the sidewalks in a bathrobe. Martin did exactly that in 1979's The Jerk.