I've had the opposite experience with hub rings. I have always run custom wheels with every car I've owned since the mid 80's. Plastic rings deform over a period of time and you have to replace them every so often. The aluminum ones do not. I've run the same set of aluminum rings for almost 10 years on my D2. I had to have them custom made back then for about $100 a set including shipping. The only thing you do is use anti-seize on the hub so they do not "get stuck."
2009 A8L W12. Alpine MRXM 55 Mono Amp, AMI, JL Audio 12TW3 Sealed PowerWedge Sub, Kufatec trunk module, powder coated calipers.