When the men are demonstrating the newly-installed door opener, a regular access door to the garage is seen to the left. Later, Sam and Darrin can't figure out how to get out of the garage when the main door won't open.
The Stephenses sat in their garage with the door WIDE OPEN. A mural painting with rocks and other things blocks their view of the driveway
and street out front of the Garage - as if they never existed. On the "Columbia Ranch," there is a long driveway and street in front of the garage. The park is kept at a safe distance. Yet, this shot on a sound stage had the mural a few feet from the garage when the Stephenses bickered and later when the Kravitzes came to spy on what was happening in the garage.
When Samantha closes the door after locking the garage door, the shade pull swings through the window where glass should be.
When the garage door opener is installed and being tested by the installers for Samantha, the door bows at the center. Obviously there is no structure or supports to the door. It is just a foam door.