First, understand I am looking into this for my own education, not to pick on anyone.
I see nothing that states the Corbeau are DOT APPROVED. Meeting the DOT standard is something different all together.
I think meeting DOT standard is clever marketing talk.
I can buy DOT brake fluid, does the DOT check every brand? No, the manufacturer is saying it meets thier spec.
Meeting thier build standards is different then having them tested by the DOT for approval, which costs big money. I learned a bit about this during my F.O.M. training threw GM.
Schrothracing does have DOT Approval for certain cars only.
From thier site:
"SCHROTH harness belts meet all certification requirements by the German TÜV, ECE-R 16.04 and US-DOT FMVSS 209 for use on public roads. Each belt comes with complete installation and operating instructions.
***THIS IS THE IMPORTANT PART****If your vehicle is listed in the included Vehicle Reference List the installation has been tested and appoved with the stock seat or the listed aftermarket seats.
SCHROTH QuickFit harnessbelts have the make and model of the applicable car printed on the tail strap label."
Can you get away with it, most likely, but strictly talking they are illegal.