Green’s Dictionary of Slang

rattle and jar n.

(US) a car.

1928		M.C. Sharpe Chicago May: Her Story in Hamilton (1952) 132: Rattle and jar – car.
1935		A.J. Pollock Und. Speaks.
1944		D. Runyon Runyon à la Carte 129: It does not look as if the old rattle-and -jar can hold the road much longer.
1960		J. Franklyn Dict. Rhy. Sl.
1963		L.F. Freed Crime in S. Afr. 106: When he talks of grabbing a ‘rattle and jar’ he means he is going to steal a motor-car.
2002		B. Kirkpatrick Wicked Cockney Rhy. Sl.