The car was filthy when he returned it to me, and 'to cap it off' [='to top it off'], there was almost no fuel left in the tank.
a 'shower/bathing cap' [=a head covering that people wear to keep their hair dry when they are showering/swimming]
They may not like being called careless, but 'if the cap fits, wear it'. [=('US') 'if the shoe fits, wear it']
(..) Uh-huh. So do I. Oops. Sorry. I've got it. Hey. Hey! Stop! You in the cap. Hey. Get back here. Come on, man. What did you get me? What I said I was going to get you. (..)2011 TvShow: Suits Title: Pilot Season: 1 Episode 1