That seems like an extreme and unneeded response given that the door already has two drain holes. I'd recommend removing the black rubber air baffles that are inserted into those two holes and check they are not clogged. Drilling holes = rust starters. Just clean the baffles, or remove them instead of drilling holes.I remember my buddy drilled a hole since the real drain holes are clogged.
In the US I would recomend Fluid film. Its lanolin based waxy product that displaces water and doesn't trap it. Perfect for places like the inside of the door panel here.That's a good point. I'd use Waxoil type spray from an aerosol can. It's what the British car guys use and if anybody knows rust it's these guys.
Indeed they were clogged with stuff4est has other issues he needs to deal with and I wouldn't wait. The "drains" that he found aren't at the lowest point, the single hole at the front of the door is. Without cleaning that there is still a pile of water in there and worse yet, sitting in the seam.
If it was my car I'd pull the door panel off, clean everything up in there and spray some rust preventing product in there like Krown or Rust Check. Otherwise the bottom of the door is going to be a rusty mess in no time.
Just my two cents...
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