This may or may not test your knowledge on rims because I have NO clue what kind of rims these are. The guy that sold the car to me had 3 of the caps but was missing one. Here is a picture of one of the symbols on the cap:

 

*Bump* Wanna know because tires look ghetto without that one cap.

 

post some more pics. its most likely one of those once that you can buy at most department store auto section.

 

Yeah, we should have a rim I.D. thread. Missing a cap my self...

 

+1 on that

 

You could just buy replacement caps, you can find caps that fit most rims for cheap prices.