Screws striped

[pola8]

Seems like the screws are striped by the back number plate light. Is this common ?

 

[Bbflex]

Mine have done this too, they have corroded in by the looks of things, I managed to get two screws out and had to drill the heads off the other two, not sure whether I will be able to get the threads out or have to strip the boot down for the trim so I can get a better angle on things.

Oh and as far as I've seen there isn't a part number for replacement screws.