Glad your son called his insurance agent, some companies won't insure salvage vehicles, and you want to know that before buying.
I don't think the government has any role trying to enact laws to protect consumers from their own stupidity.
If you can't evaluate a used car properly, have a pro give it a look over. If you do neither of those and buy junk, well that's your own fault. If it is still too frightening or risky, buy or lease a new car with a warantee, even if it is a cheap econobox.
Every single person I have known that bought a salvage vehicle did it because they wanted what is too good to be true. They had a Kia budget but wanted a Cadillac, so they buy a "smoking deal" salvage vehicle so they can drive more car then they could have afforded. Some had major problems, some did not. All of them were told by the seller that the car was salvaged due to a "minor accident" which required a willing desire to believe on the part of the buyer.