A rim protector on a diamond-cut wheel
A diamond-cut wheel has a machined face under clear lacquer. Two sources disagree about putting a rim protector on that face. We haven't fitted one on a diamond-cut wheel.
Can AlloyGator go on a diamond-cut wheel?
AlloyGator's suitability page says the ring can be fitted to machine-polished and diamond-cut alloy wheels, and then it lists the catch. Those wheels have a lacquered surface. Existing lacquer damage is not always visible. If minute damage is already there, they say fitting the ring may raise the chance that moisture stays put and the lacquer degrades faster. If you fit it yourself, they say you have accepted that warning.
The same answer says fitting the ring "will not cause damage on their own." That sentence is theirs. It sits next to the moisture warning, so read both. They point to a separate machine-polished disclaimer on their site.
What did an owner say?
On Tesla Motors Club, in a thread about matching a protector to the wheel color, flowuk wrote: "never put Alloygators or similar on diamond cut alloys. Dirt & damp over time can remove the lacquer & totally ruin them." He opened with "Not an issue with any of the Tesla rims (i don't think)." He was guessing about Tesla wheels. He was plain about diamond-cut alloys in general.
That post is one owner. AlloyGator's page is the maker. They don't say the same thing, and we don't have a test of our own.
What about a stick-on strip?
The Rimblades fitting guide doesn't use the words diamond cut. It does say the strips should not go on a ceramic-coated wheel unless that coating is professionally removed, because the coating is a non-stick surface. Tyre shine, silicone left by a tire fitter, and some brake-dust coatings also stop the tape. If the wheel was just painted, they want the paint to cure for at least a week first.
All-Fit's install page doesn't mention diamond-cut or lacquer. It says the rim edge has to be free of oil and grime or the adhesive won't bond. That is a cleaning step, not a finish warning.
AlloyGator · Rimblades · Color · Rim protectors on alloy wheels · Rim protector colors · Prep a wheel for a stick-on rim protector