This may be a silly suggestion, and appreciate its not an ideal fix, but could a sheet of perspex be cut to fit all the way down inside the door so its wedged between the door bottom and the window frame? Perspex will probably tolerate being manhandled into place like this, and once in, should stay put?
Obviously its far from ideal, and won't move once fitted but if its the difference between being able to go out in the car or not, or staying dry on a rainy day and not, then might it be worth a look?
Looking at 6c's photo, it looks like a session with a metal folding machine might be able to make something similar?
Option B, does anyone have a metal channel thats not fitted to a car, but which could be used as a template for a fabricator to make one or many replacements? I'd like to imagine a man in a shed somewhere could probably create something that would work for a reasonable fee? And if you got 5 or ten made up then you could probably sell them to club members and have whats effectively a free fix for your LNA?
I may be talking utter tosh though.
2003 Toyota Yaris
2004 SAAB 9-3
1998 Toyota Celica ST
1996 Nissan Almera GX (departed)
198? Jago Geep (Now resideing chez red5)
Yeah yeah, another blog. Why I use silly hardware to mine cryptocurrency: https://piminer.home.blog/