You are very welcome. Vivid is full of crap. The Enkei's don't come with them. That doesn't mean they "don't use them."
Hub Centric almost never come with aftermarket wheels, at least not from the wheel manufacturer. Like lug nuts, the rings are typically made by another company. Just because wheels don't come from Enkei with lugs doesn't mean they "don't use them." It's the same thing with hub centric rings.
As I said above, America's tire will look up the center bore of the inside of the wheel, and the center bore of an MR2's hub (which is 60.1mm if I remember correct). Once they have these numbers, they will order the hub centric rings with the correct inner/outer bore.
There are two types of rings, plastic ones and metal ones. Get the metal ones. Plastic ones can melt. America's Tire should be $10-15 for a set of 4 metal ones.
Here are some pictures of a set of 4 metal hub centric rings. The rings you get from America's tire are nice anodized aluminum rings like the ones in the picture below, so they will not rust.
http://www.motorsport-tech.com/img/gallery/rings/1.jpg
This is a picture of a guy installing hub centric rings. You can see, you put the ring in the middle of the wheel. The ring you by after they look up the measurements fits in the center of the wheel, and then this will center the wheel on the hub when installed (like stock).
http://www.wildweasel.ca/HowTo/Auto/.../hubring_1.jpg
Here's the ring installed on the wheel
http://www.wildweasel.ca/HowTo/Auto/...l/hubring2.jpg
Here's a picture of the ring next to the hub.
http://www.wildweasel.ca/HowTo/Auto/...l/hubring3.jpg
Here's a picture of the ring on the hub. You can see it's centered on the hub, so the wheel will be hub centric
http://www.wildweasel.ca/HowTo/Auto/...l/hubring4.jpg
There pictures are from the web article: HOW TO: Correctly Install Aftermarket Wheels Written by Wild Weasel
Here's a link to the site
Wild Weasel's Automotive HowTo Pages