Derek, everyone on here is leaving out a very important point about these "spacers" that I'm sure is leaving you in the dark...
You would be totally correct if these really were just spacers (rings slipped over stock studs) but they aren't. They actually have to use a CNC'd piece that BOLTS to the stock studs (just like the wheel does) and then has it's own studs that the wheel bolts to.
While, not ideal (better to get rims with the correct offset BUT the selection is almost ZILCH for these cars) it is still very safe due to not really just being a spacer.
Oh, ok.
I had a 1984 50th Anniversary edition (The Gold and Black one) Nissan/Datsun 300 ZX with wheels set up (on the front) like that. Thanks for the clear up.
I also agree with what you said :..............."While, not ideal (better to get rims with the correct offset BUT the selection is almost ZILCH for these cars) it is still very safe due to not really just being a spacer."