They still plug (tubeless) tires on the car. Pull out the nail with pliers, ream out the hole, use another tool to stick a sort of sticky rope into the hole and cut the rope flush with the tread with a razorblade.

Or at least that's what they did when I picked up a nail last month. I would have rather they used a mushroom-type plug that also had a patch on the inside, but I didn't have time to argue.

As far as patching the sidewalls, there may be individual state laws and liability concerns, but Federal laws typically govern new car manufacture, not repair post-manufacture. There might be something that regulated commercial trucks.