Unscrew the tire valve caps, apply mighty bond on the treads, and quickly screw it back on. Repeat for all 4 tires. After a few weeks, he'll decide to have his tires inflated....hehehee... he'll have a fun time trying to unscrew his tire valve caps.

If there is a security camera, bring some stuff (e.g. groceries) and accidentally drop it and make sure some items roll near his car. While you're picking up your stuff, that's when you do your magic.