I am about to replace all the plastic in my 1977 172. I know a couple of you have done this before. My question is, is there a need, or has anyone put any soundproofing or isulation behind the plastic (I am particularly thinking of the panels below the rear windows.) If so, what kind did you put in?

Also, if anyone has any ideas or gotchas that I need to look out for I would appreciate hearing about it.