One general warning about coro discs (from experience): keep the edge of the disc off the tire itself. It's sharper than you might think, and over time can cut into the rubber if it's in contact, even at a shallow angle.
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Here's one of several iterations I've done:
The Premier's Limo: 2004 Toyota Prius "winter beater" ecomodding thread
In this case, I drilled into the OEM plastic trim ring that goes on the OEM alloy wheels. Here's the trim ring:
