Green’s Dictionary of Slang

don’t make a fuss n.

a bus.

1960		J. Franklyn Dict. of Rhy. Sl.
1964		R.S. Gold Jazz Lex. xxiii: British formations in which the meaningful word, whether slang or standard, is usually replaced by a nonsense rhyming one: e.g., Kangaroo: a Jew; don’t make a fuss: a bus; down the drains: brains; Colney Hatch: a match.