When Jill pretends to be hit by a car, she drops the blueprints she is carrying in the street. Roy David, however, picks them up from the sidewalk.
As Sabrina is backing up to leave The Paddock, her orange Pinto has no headrest and no rear-view mirror. It was standard procedure during filming that various parts of a vehicle be removed in order not to obstruct the actors.
Roy David pulls up to the office building, looks at the directory, then questions the man coming out of the building about "Kelly Duncan" in less than two minutes. It is implausible that a meter maid would have been able to issue him a ticket in that short amount of time.
When Roy speeds out of The Paddock parking lot after losing the bet, shadows of several crew members are visible on the pavement.