i got a set of aftermarket 18s and they do not sit on the rotors in the center like OEM wheels would. what is that part called that you put in between the rotor and the wheel so that the wheel sits firmly and isn't being held by just the lugs?? its not the wheel spacers, it is? thanks.

 

hubcentric rings you mean?

 

probably yes, never dealt with them basicly its the part that lets the center hole of the rim sit tightly on the hub (otherwise it is held only by the bolts if i would install them like that)

 

yes that would be hubcentric rings. I recommend you get a set of those