He keeps a jack and spare tire in the 'trunk'.
a 'trunk' full of clothes
the 'trunk' of an artery
(..) MARVIN: Get home to your mama, boy. THUG : Biff! THUG : Hurry, Biff! MARTY: Let me out of here! Reginald, where are your keys? MARTY: The keys are in the trunk. MARVIN: Say that again? MARTY: I said, the keys are in here. LORRAINE: Let me go! BIFF: Come on! (..)1985 Back to the Future