Green’s Dictionary of Slang

Clifton brick n.

[rhy. sl. prick n. (3)]

(Aus.) used as insult, a fool.

[Aus]Sydney Morn. Herald 31 Mar. 15/3: [T]emper matters with rhyming slang. For example, when abusing another driver out the car window, they will call him a ‘Clifton brick’ [Simes:DLSS].