The scene where young Robin drives up to the gate and the car stalls was not scripted. Apparently, Jason Marsden didn't know how to drive a stick shift! It was so funny that the producers decided to leave it in the movie.
Adam West and Burt Ward had input on who was cast to play them as Batman and Robin in flashbacks in 'Return to the Batcave'. Jack Brewer (Batman) and Jason Marsden (Robin) were the lucky winners. Adam and Burt helped the actors research the roles and worked with them on their mannerisms.
Frank Gorshin, the Riddler, stirred up trouble again with fellow "Batman" villain Julie Newmar in 'Return to the Batcave'. The movie was a reunion of sorts not only for the cast, but the crew as well. The Director of Photography for 'Return to the Batcave', Jim Glennon, was the assistant cameraman on the 1966 series. And Casey O. Rohrs served as the Editor for the movie because his father edited the original series.
Some scenes were filmed at Bronson Canyon Cave where the original series shot the Batmobile driving out of the cave. While filming inside of the cave, production was halted because of a real bat that was flying around!