I can tell you there is a company near South San Francisco that sells/moves A LOT of JDM vehicles. And if you click on "other Ads for CL seller," they currently have over 10 other listings. The photos are local.
"We import these vans. ... CA registration may require emissions conformance even though pre 97 diesels are smog exempt. It is expensive to do. All other states don’t require this as these vehicles are federally epa emissions exempt. "
"No, these cannot be registered in CA."
They told me they send these to other states. I wrote asking them if they have ever had any of these JDM registered in Calif or if they know if any of them have returned to CA and been registered here after being registered in another state.