Source for capacitive touch panel (Navigon 8410/8450 car GPS) or fix?

[Greybeard]

I've got 2 Navigon 8410 car navigation systems with non/bad responding touch panels.
The devices are old, but have very nice GUI, so I'd like to repair them.



One touch panel does not respond at all, the other one has a small in-responsive area about in the middle.

Problem:
I could not find a source to buy these capacitive touch panels:



Maybe there's just an open solder joint or similar...

Maybe some touch screen expert can help?
What's the usual failure causes?