Someone's planning to jump me and steal my car. What do I do?

So this guy is mad at me because he thinks I intentionally disrespected his girlfriend who I work with and for the past week has been coming to where and work and pretending to be friendly, asking me what time I get off. She being the bad person that she is, probably encourages it. Just yesterday he came up to my car and asked if he could take me to his house real quick. I said no I have to go back in to work and he left in his own car, which made even more obvious that they had something planned. Probably had a lot of friends there and were going to beat me up steal my car and others things I have. What do I do in this situation if he keeps it up?