I have a 2002 Audi A6 2.7T with the OCT Chip and just under 40,000mile on the car. I have installed 18x8.5" 30 MM offset RS6 9 Spoke rims with Continental Extreme Contact tires on the car. For some reason I am getting vibration at 48mph and 77mph everything on the car checks out fine. I have had the tires and rims balanced on the Hunter GSP9700Road Force machine4 times and every time the tire/rim specs are coming in well withinnormal specs. Are Continental tires just junk, I was told these rims need no spacers is this correct-HELP!

 

You never installed hub centering rings. A lot of tire shops won't give you these for free, and are too stupid to realize that it needs them. A centering ring goes on the hub before installing the wheel so it fits flush against the hub. If they aren't on there, the tire will flop around like a fish at higher speeds on the hub. Trust me...