At the end, the Douglas's pull up to their new farm in a Lincoln Continental convertible with the car in view of their house, then in the next same shot there is no car visible.
While driving to the farmhouse in their convertible, the head-on camera angle clearly shows a rear view mirror mounted on the center of the front windshield. As they drive in the next shot angled about 45 degrees from the front side, the convertible no longer has a rear view mirror on the windshield. However, when the Douglas couple arrives at the farmhouse in the next shot and the camera returns to straight-on angle shots from both the front and then the back of the car, the rear view mirror appears again on the front windshield.
In the opening sequence, when Oliver reaches in to pull Lisa from New York to the farm, she changes from a dress, to a a casual jeans and shirt ensemble, while Oliver remains in the same suit he was wearing originally. It may or may not be intentional to emphasize the transition.