66.1mm is the stock hub size. Anything different is a potential problem. If it is too close to that, I don't think hubcentric rings are made that are that thin. I can't say for sure that 66.5mm of Anton's wheels is the problem for the vibration, but I would rather have a wheel bore that is 73mm and use hubcentric rings. I definitely would not buy from a retailer without having the hubcentric rings as part of the purchase.

Do you guys realize that the factory wheel center bore is probably very close to 66.5? 0.4mm difference is nothing. If you actually try to put a 66.1mm bore on a 66.1mm hub you are going to have a very hard time getting it to slide on. Get yourself a caliper and actually measure a factory wheel against a factory hub. Think about it, the slightest bit of oxidation on the hub or wheel would freeze a wheel right on it. You do not need a hubcentric ring for a 0.4mm difference. You need that 0.2mm gap just to get the wheel on the hub easily.
Now if we were arguing about 4mm of difference, then yes you should get a ring for that. But we are talking about 0.2mm around the hub.... That's insane to think you need one or could even fit one there.

Edit: The width of a human hair is about 0.1mm, so go on and wrap something that is 2 hairs thick around the hub and slap you wheel on and call it a day......