Basically what is happening is the foam under the deck eventually compresses enough after being walked on, etc. that there is a void between the bottom of the deck and the foam. The squeaking noise is coming from the aluminum and the foam rubbing together when weight is put on it. What I did was go in from the small storage compartment directly behind the seat, right or left depending on your situation. Pull out the plastic lining tub and you will see the yellow foam. Cut a hole just big enough to work from, mine was about 4" X 4". There is a piece of channel aluminum running at an angle that is riveted to the decking with three rivets. You will need to cut away the foam that is around the sides of that brace as it is causing the majority of the squeaking noise. When you are done you will not want any foam touching that brace. Then I cut away about 1" of foam away from the deck so when weight is on the deck it will not touch the foam at all. You will probably notice that there will already be a gap there if you are experiencing the squeaking. After the foam is cut away from the top I stuffed shop rags into the gaps just to put some support back in there. I don't know if that is necessary or not but that's what I did. After that my deck is as quiet as can be and there is no sign of any soft spots or weakness in it whatsoever. To cut the foam I took the blade out of my hacksaw and just pushed it through the foam and started cutting it with my hand. It cuts the foam very easily and it makes for a nice neat cut also. I hope this will help anyone else with the annoying problem I had and it really is a fairly easy fix.