What should be my next move?

Going by what you've said, I can't say for sure whether or not he likes you. But, I can say with relative confidence that there is potential for you two to really hit it off. I'd advise you to go into his work (make sure you're actually going for another reason too though, buy something that you actually need) and just happen to bump into him. Say something along the lines of "Hey, did I ever thank you properly for the lift? I appreciate it, you know? Oh hey, fancy hanging out sometime?" Also, if you drive, offer to do so. Think about it, some guys actually want girls to be more forward, it seems like he's given you the go ahead, so go get him ;)