Corrected entry: Near the end of the movie Howie dresses up in a Turbo Man costume, with real working discs shooting out of his arms, and a real working jetpack loaded with fuel on his back. It seems unnecessarily extravagant for a costume, unless the real Turbo Man actor was supposed to do some kind of a stunt as part of the show - but that would have been very dangerous in a public place with no wires or safety net.
Corrected entry: Arnold is chased by the Police Officer through some busses, but it's Christmas Eve, when there's no school, so there would be no need for busses to bring students to the parade.
Corrected entry: when Jamie is describing the Turboman doll to Arnie; Jamie says: "accessories sold separately, batteries not included"; but in a later scene, when Arnie is breaking into the neighbours' house to steal his Turboman doll, he shakes it and it says "it turbo time". Where'd the mystery batteries come from?