Looks like there's a lot of competition already.
There looks to be performance standards in place complete with a tiered rating system.
I don't know if there is a certification process [that would mean destructive testing ]...otherwise it would be anything goes as far as the manufacturer's safety claims are concerned.
Here's a sample of what's out there.
https://www.alpineco.com/available-now/ ... mored-suvs
[click on ballistic testing]