They are a retaining clips and one is located on one stud of each wheel. They are put on at the factory to keep the wheels on as they move down the assembly line. The factory wheels have a relief on the backside so they "usually" don't affect those. Aftermarket wheels could be affected by them.

FWIW, these aren't anything new. Auto manufacturers have been putting these on cars for as long as I've been working on cars and that goes back to the late 60's.

They really don't serve a purpose except while going down the assembly line so just go ahead and take them off.

 

I had the stock wheels and they did affect mine. There were two on one side and one on the other. There wasn't a vibration that I felt but I could hear it.

 

If your rims have a depression on the mounting flange where the
clips would be like OEM wheels, the clips are not a problem. If you
aftermarket rims dont have the same depressions, the mounting
flange wont sit flush and the rims will not be running true, hence the
vibrations. It also effects the flatness of your brake rotor as the
tightened lugs will deform the hub and cause the rotor to be deflected.
Also the lugs have a chance of loosening up because of the clips
and the inability of proper torquing of the lug nuts..

 

I need to look into this. Im getting a slight vibration @ 75mph.

 

Road force balance ftw.

 

True about the lugs. Mine were loose.