Driver side front door before and after.
Passenger side rear door. Not as pretty, since I used leftover pieces.
Same door. Now you can see the foil in the unused speaker opening instead of cold steel.
On a quick test drive I noticed two things. The sound of the electric motor was more audible than before. I guess when you reduce other noises you start hearing others. I also noticed that the bass frequencies sounded louder on the car stereo. To be expected, since adding the insulation makes the doors perform better as speaker enclosures.
I'm also planning to add some anti-stone chip shield behind the front wheels. There doesn't seem to be much to speak of. It could also make the car quieter. At least concerning noises made by flying stones, if nothing else.