Rust for license plate lighting – still to be rescued?

Meal, with my 06 Golf Plus they failed to take care of the well-known rust problem about the license plate lighting early on – with the now unsightly consequences for me. I tried to get VW for it, but it will probably stay stuck on me. Since the car is in my possession, I regularly grease up there, so that the rust does not wander around the tailgate, but this is not a solution in the long term. So how are the chances that I’m afraid that if I remove the rust there, there’s nothing left to build on. Edit: due to construction, it rusts there from the inside to the outside. Best regards