Green’s Dictionary of Slang

(US) out-of-date, cheap; also as n.

1932		(con. 1929) R.E. Burns I Am a Fugitive 172: He drove an old model-T that could not make over twenty miles an hour.
1942		R. Chandler High Window 90: I hear how in Noo York they got elevators that just whiz [...] Must take a good man to run them fast babies. [...] Now you take a Model T job like this – it takes a man to run it.
1943		W. Guthrie Bound for Glory (1969) 175: We moved in an old T Model truck.
1944		Post (Lanarks) 23 Apr. 6/2: Model T — old.