Yep, that would be the ideal way. OTOH, will never happen because there is no such certification system in place even for new cars (and not only Tesla's). New cars pass the homologation process where a few specimen are subjected to various tests (e.g. crash testing and emission tests) and a lot of paperwork is done by the manufacturer certifying compliance with various regulations.
That's not realistic for a repaired car. You can't crash-test a one-off vehicle which is the only way to determine structural soundness of some of the repairs he is doing.
That's also why such car "recycling" is generally not done. If anything major in the chassis/body is damaged, the car is usually a total loss - it is not economical or even possible to safely repair it and nobody could guarantee the safety of it.
The best he can do is to become an authorized mechanic for Tesla (not sure whether Tesla has such program, never owned one). But then he would likely be legally unable to use salvaged parts in his repairs, only new ones.
That's not realistic for a repaired car. You can't crash-test a one-off vehicle which is the only way to determine structural soundness of some of the repairs he is doing.
That's also why such car "recycling" is generally not done. If anything major in the chassis/body is damaged, the car is usually a total loss - it is not economical or even possible to safely repair it and nobody could guarantee the safety of it.
The best he can do is to become an authorized mechanic for Tesla (not sure whether Tesla has such program, never owned one). But then he would likely be legally unable to use salvaged parts in his repairs, only new ones.