The door panels are a hard cardboard and the previous owner must have left the window open too many times because the are a bit warped. Anyone come across any good ideas on how to fix them? Can i get them wet again and keep weight on them?, etc...

 

Use a blow dryer with the re-wetting method

Most people just buy a thin sheet of plexi and swap over the carpeting trim etc
Stronger lighter and will not warp or distort from moisture or much of anything else