What is a good gift for a guy who does his own vehicle maitenance and repair?

My bf mentioned about a month ago that he was having car trouble and a Radiator Cooling System and Pressure Tester Kit would be good to have. I considered getting him this but once I found out if was around $100+ I am now reconsidering. Can anyone help me with any good gift ideas?? He loves working on his car so I'd like to get him something with that theme.