Vehicle regulations... where to find them?

Anyone know where to find vehicle regulations for Federal and state approval?

I figure there's the DOT/NHTSA, EPA and then each state has it's own motor vehicle department? I've looked on the web sites of each Fed agency and didn't find much.

They either don't care or don't know. I'm in CA and I found the most info from the BAR. http://www.autorepair.ca.gov/stdhome.asp

I had to call and talk to the head tech to get actual information, (800-952-5210) everyone else in the chain from DMV to Highway Patrol knew zip. It was almost funny in a way because in the begining I called many different DMV offices and CHP stations in search of info and I got all kinds of different and conflicting answers.

Basically I never got a straight answer from the DMV or CHP, but I built my rig anyway. DMV was a joke, they didn't even look at it! CHP just looked for serial #'s to see if it was stolen. Brake n lamp test. Then the smog check by the state referee and I was done!!! Insurance is thru AAA, but they're insuring it as a '99 Chevy because their computer doesn't have a "kit car" "spc const" "other" button.