The triangle hole version is very rare, at least in North America. I've got dozens of hubcaps (have I mentioned I'm a packrat?) collected from the many, many cars I've parted out over the last 40 years and I think I may have one or two of them. By the way, the reason the caps come off the car easily, and walk around and cut the valve stem as well, is that they or the retaining clips are too stiff. Steel wheels bend a remarkable amount on the road (both out of round and laterally), and the retaining clips "walk" over the wheel's rim as a result. I once tried gluing a bit of rubber to the wheel, so the cap couldn't walk forward or back, but after a couple of weeks that cap flew off the car and was lost. Obviously a reach to link the two events, but it seemed plausible and as that was before I had dozens of them I stopped experimenting.
Yours
Vern