Rear license plate bolt replacement

Just trying to picture what's broken. Originally there was a hole in the hatch lid, and on the inside a tack-welded nut. You put on the license plate, then pass a machine screw through it's mounting hole, the hatch lid hole, and screw it into the tack-welded nut.

Assuming it's like that: what's broken: did the tack-welded nut break loose, or the machine screw's head snapped off?

 

I have the same problem, did you ever find a fix? On my car, the bolt head is snapped off and the remainder of the bolt is rusted in. Tried using an easy-out but it did not work because the remainder of the bolt seems to be some kind of impenetrable space age alloy. Watched some YouTube videos on hatch handle repair and there doesn't seem to be easy access to the bolt from the inside. Stuck at this point, may not ever be able to move to another state.

 

Maybe research "bolt extractor". You center-punch the bolt remnant, drill a small pilot hole, then drill the appropriate sized bolt extractor bit into it. It has reverse direction, aggressive thread, that hopefully bites in within the pilot hole, and spins the bolt remnant out.

I've found you have better luck if you go one size larger than the recommended pilot hole size (usually there's a table with the bolt extractor kit, or you can find tables on the 'net.)

The main issue I found is to get a decent centre-punch roughly in the middle of the bolt remnant, and a pilot hole that doesn't drift off to the side too much.

If you remove the rear license plate every time you wash your car, put a drop of oil put on the threads, this doesn't happen. I know, hindsight... Also, reinstall the bolts temporarily, fully in, while hosing the car, to avoid water ingress.

With a bit of prying off of interior panels you get at the other side, the tack-weld nuts on the inside, but there's no big advantage: I would still drill from the outside, keep the mess and shavings out of the car.