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']
(..) zombie goes down in front of me.. Ever roll a tube of tooth paste up from the bottom? - Yeah. I always rolled up from bottom to top. - Yeah, zombie's head is the cap. Do you know this guy who's trying to like.. to be in everyone's story? No. I knew who got away worse than that to me. (..)2009 Zombieland