What's going on here?!
 

This day just keeps getting worse. Tried to mount my wheels to the car this evening and the won't go on on due to the sixth bolt pictured below (the back of the wheel hits it). Does anyone know what this is? I bought this car used and this was already on there when I picked it up. My guess is that it's a spacer but not certain.

Take it off its only there to keep you from mixing the stock wheels front to rear not needed for custom wheels

:iagree: what he said

Interesting. For the base 18" I assume?

You can remove it. Used to break the rotor from the spindle, under normal conditions you would back the bolt out remove spacer then tighten the bolt back in which will break the rotor free from the spindle. I am assuming you are trying to put on some after market wheels.

Yes, trying to install some Work GS4s.