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']
(..) You are free to try and stop me. Business is business. Prepare five horses for them. I want everybody up at the crack of dawn. Yes sir. Understood cap. Carrying glass would be hard. We need to get ahead as far as possible. We'll divide into two groups. Fitzgerald, Jones, fryman. You (..)2015 The Revenant