After this post I tried hitting rocks, scrap cars, scrap metal piles, a frequency jammer and a few walls and nothing happens on any of these things. I'm guessing the sledgehammer's powers haven't been implemented yet. Hopefully soon.
So, are you saying that once the server restarts the trader will lose the vehicle and it will respawn?
Or, does the trader still have the vehicle for sale and the vehicle respawns also?
I really hope the latter is not the case.