Just thought I would share this info….I hope it could help some people.
I bought a set of 19” Roja wheels for my car about 6 months ago. I installed 15mm H&R wheel spacers with the initial set-up. The car seemed to ride a little rough and slowly became worse. I thought it was the wheel spacers so I took them off. The car was ridding fine again for about a few weeks and then slowly went right back to a severe rough ride??? Hmmmm. Long story short, I was in need of Hub Centric (Spigot) rings. The TT has a hub size of 57.1mm. I always thought you find a set of 5x100 wheels with the correct offset and you were off and running….that’s a big negative! A 5x100 wheel can fit many different cars. My after market wheels have an inner hub bore size of 71mm! So the wheels were never resting on the hub. The weight of the car was resting on the bolts. Even with the bolt hole aligning, you can never by dead on.
I bought the right Hub Centric (Spigot) rings and my car rides perfect at all speeds.
http://www.1010tires.com/hubrings.asp

 

Also, a word to teh wise...

if you happen to have plastic hub-rings, make SURE that you take them off prior to taking a torch to the hub to loosen the rotors, when you go to change them, because plastic, ummm... melts when you apply HEAT, apparently[:@]. next brake job I replace my plastic rings with aluminum ones

 

The aluminum ones arent much better. They corrode to the iron rotors and you have to air hammer them off. Pretty much destroying them in the process.

 

Yes, a hub-centric fit is also much stronger than relying on the lug bolts or studs to hold the wheel on. Your lugs will last longer with a hub-centric fit and not require as much torque to hold the wheel tight (meaning you can back off on the torque andstretch the threads less each time you mount the wheel).