Because my car eats almost whole family budged, I have decided to recycling maximum of used materials.
On this picture are bitumen sheets glued on both sided tape used in my old front doors.....
and installed back in my left sliding doors.
Then was second soft foam layer applied.
And finally third layer from factory damping material.
On this image are left sliding doors finished.
After that I have applied soft foam layer on the drivers doors.
Third layer on both front doors are made from 2mm thick metal sheet with factory damping material glued together and kick bass pods made from MDF. On the lower half sealed with common bitumen tape.
The third layer is secured on the front doors using aluminum rivets.