About 34 minutes in, in the background driving back from picking up Rod from the airport the same parked white SUV and grey pick up appear three times within a few seconds.
When the duck comes out of the water after pulling Paul the dog into pond (around 31 minutes) and sits on the golf ball, the film is reversed to make it look as if it is lowering onto it while, in fact, it is actually raising up off of the golf ball.
Early in the film the main trio take a flight from T.F. Green International Airport in Providence, Rhode Island, to Atlantic City. However, there are no direct flights offered from Providence to Atlantic City.