Here's one I really like:
https://drivemag.com/news/memminger-...ally-isn-t-one
This says it has a tube frame and there is a Youtube video that speculates it's based on an old Beetle. But those are New Beetle door handles and similar doors and running boards. The rear valance is New Beetle.
My best guess is a New Beetle body (possibly even a sedan, the windshield isn't a good match), gutted, with a tube subframe to carry the Type IV flat four and five-speed. Superbeetle-style fenders to fit new Beetle quarters. A Mexican Super front bumper.
I like the Porsche 918-style roll bars.