I got some konig 17 in rims off the internet and went to goodyear for some tires and got the tires put on them but they said they couldn't mount them because i didn't have small enough lug nuts and they said i need a center cap maybe? They said that the wheels should have come w/a center cap to keep them from sliding up and down. Does anyone know if this is true or can i just tighten the lugs extra tight. IF i need one where the hell could i get one for these rims? Thanks alot for your help