Magical Mystery Tour
This cartoon conflates Magical Mystery Tour and Yellow Submarine, as the Beatles characters here are based on the Beatles characters from the animated film Yellow Submarine created by Heinz Edelmann
In the cartoon the coach from the Magical Mystery Tour has come to a stop at the top of a rainbow, which is a reference to the hippy psychedelic drug culture that was prevalent at the time of the two films. The Beatles are standing on the rainbow, with one of them asking “What did you put into the sat-nav John?”. Part of the joke in the cartoon is that sat-navs (GPDs) didn’t exist at the time. There’s also a double meaning it the phrase “What did you put into the…” as this can refer to putting hallucinogenic, pychotropic drugs such as LSD or other mind-altering drugs into such things as drinks, cakes etc.