fuel cell question
Regarding mufflers behind the rearend,it works great and controls sound alitle better than having the mufflers under the backseat,also makes it possible to fit larger mufflers on most cars if they are equiped with a fuelcell and has no sparetirewell,leaving a bunch of space for mufflers.
Back on topic,i never had a problem with the foam deteriorating in my old Jaz fuelcell and like the foam since it cuts down on how much the fuel can move around.