Goofs

While Eunice decides to take Howard's rocks back to his room, she hurriedly puts her wig on and it teeters on her head messily. When she opens her door and walks down the hall, her wig is neat and fitting perfectly.

At the airport Howard stands in front of a departure sign that says local time is 11:08, yet just a few minutes later Eunice tells Mr. Larabee that it's 12:05.

When the cars chase the three wheeled bike, they drive from a hill with a STOP-sign. On the right, viewers will note some parked cars (Chevrolet Corvair, Ford, Pinto and a Rover). In the next shot, when the Cadillac limo passes, the three cars have disappeared and have changed into a 1971 Chevrolet Vega coupe, Chevrolet Caprice coupe, Triumph GT-6.

When Mr. Jones is following Mr. Smith at the beginning of the movie. Mr. Jones gets into a cab where the cab driver is very noticeably bald. But when he gets out later on, the cab driver has a lot of hair blowing in the breeze.

When Mr Jones jumps off the balcony in the last party scene, he has golf clubs over his shoulder. When he lands on the thug's back the golf clubs have disappeared.

Throughout the film Howard strikes several rocks with tuning forks, and then listens to the tuning fork as if he's expecting a different tone when he hits different rocks. Tuning forks are made to resonate at a fixed pitch, so no matter what object is struck with the fork, it will always sound the same.

Contrary to popular belief, VW beetles do not float on water. They may float for a few minutes due to their structure, but they soon sink as any other car would. The VW driven into the bay sank to the bottom, and a second had to be used for the scene where the car is floating.

In the hotel room when Howard is trying to turn off the television, it has no electrical power wire plugged into the wall. When he pulls the cable out of the out of the wall it causes sparks and starts a fire. The cable wire does not have enough electricity running through it to cause sparks let alone start the room on fire. Without electrical power, the television shouldn't be on in the first place.

Howard mentions that his theory is that ancient humans used rocks to create prehistoric music 7 million years ago, but that is the time when chimpanzees and primitive humans split on the evolutionary tree, so at that time primitive humans were little more than chimps. Hardly able to create, or even appreciate, any type of "music." Hugh (Kenneth Mars) says that Howard is studying "Neanderthals", which evolved roughly 250,000 years ago (and could probably create the music with rocks that Howard postulates).

Throughout the car chase (near the end of the movie), the "Just Married" VW is a post-1967 Beetle. However, it is a pre-1967 Beetle that is later seen floating in San Francisco Bay. This was due to the fact that the first car sank into the bay at the end of the chase scene, necessitating a second car "prop" for the "floating beetle" shot (Ref: Peter B in the DVD commentary).

When the sign worker falls off the ladder, the giant pane of glass breaks before his feet reach it.

When the sign worker falls off the ladder and swings down to break the pane of glass, his support wire is clearly visible.

When the VW Bus is struck repeatedly during the car chase sand can be seen spilling out of the engine compartment in the back. This was obviously a junk van with the engine and powertrain removed and the sand added presumably to make up for the missing weight. The bus, when rammed by the black 1969 Cadillac DeVille convertible, is not the same one seen earlier when rammed by a 1953 Cadillac Fleetwood 75 limousine and the taxicab. This particular bus was a prop.

As the bike begins to roll backward down the hill, the pedals force Judy's feet to turn backward, indicating it has a Derailleur-type hub, which can only freewheel in the forward direction. In the longer shot that follows, her feet on the pedals are not moving, which would require that the chain be removed.

Throughout the chase scenes at the end of the film most of the streets are completely empty of people or other cars.

The fenestration of the hotel rooms as seen in the first establishing shot is quite different from that in the interior scenes, nor does that shot show any ledges from which Judy could later dangle.

At the movies end, as the plane has just taken off from SFO, Howard looks out the window to see the Bay Bridge as the sound of "The Merry Go-Round Broke Down" begins. (This signals the start of the Warner Brothers Looney Toons.) But no airline ever started in-flight entertainment 2 minutes after take off.

Hotel Manager escorts Howard to call an elevator, whereupon fingers are clearly visible sliding said elevator door open, and are visible again upon closing.

Shadow of camera and crew clearly visible during the car chase.

After Eunice sends Howard off to the banquet, the next scene has Judy in Howard's room, dealing with the torn jacket and discovering the invitation to the banquet.

The next scene has Howard arriving at the banquet, where he interacts the head waiter, Hugh Simon, and Mr. Larrabee.

But as he reaches his table, Judy, who was dressed in street clothes when in Howard's room, is now in evening dress, and has seemingly been at the table for some time regaling the attendees with stales of Howard's deering-do.

Judy could not have changed clothes, arrived at the banquet, and established a relationship with the people at her table in the time it took Howard to leave Eunice's room and arrive at the banquet.

When Eunice is arguing with the badge lady over her identity.