Green’s Dictionary of Slang

1. (N.Z. prison, also Tupperware container) a deceptive individual.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 194/1: Tupperware (also Tupperware container) n. a person who is plastic, i.e. false, deceptive, not what he appears to be.

2. (N.Z.) a dismissive term for any ostentatious external embellishments of an automobile.

2003

McGill Reed Dict. of N.Z. Sl.