I bought one and was alittle confused by all the pieces, too. Once you lay all the pieces out on the ground you can figure out where they go. Better yet, lay them out in the car once you have removed the seats and carpet.
Personally unless you just want the factory look, that nobody will see except the trunk I would go with dyno mat. That factory stuff really doesn't do any good in my opinion.
If I remember correctly, it needs to be heated to be "attached" to the car. The original cars it was done like that and will have to be duplicated, if you want it to fully work.(it will work just by laying it in there, just not as well.)
Personally unless you just want the factory look, that nobody will see except the trunk I would go with dyno mat. That factory stuff really doesn't do any good in my opinion.
Those "sound deadner" kits are junk. Die cut flimsly graniy stuff that barley covers anything.
Do yourself a favor and go to Home Desperate and pick up a roll of Tri Ply, or rubberoid modified roofing, comes in a roll, and you can cut and weld (with a butane torch) this stuff to conform to the entire interior, I just did my 67 Coupe , every sq. inch, and my car sounds dead and tight as a drum.