Rear wheel insulation??

Finally got everything out and documented (so I remember how to put it all back together) down to the insulation in the back.  THe question is over the rear wheels are hard foam insulation with some clear plastic covering.  It is molded over the body.  When I replace the insulation with the reflectix should this hard foam covering come out and be replaced, or put the reflectix over it? The passenger side is in great shape  but the driver side is in pieces only held together by the plastic covering but could still be used probably, if I am careful.
FYI I was really pleased when I tore up the insulation over the floor pans.  Barely any rust and only surface rust at that and even then only in spotty but plan to coat with POR 15 anyway.
Thanks for any help and suggestions.
BW

Not being able to see what you have, I would probably suggest you apply your heat barrier product directly to the body, and the factory insulation over that.

It's nice to tear into a project like this, and not have any surprises, like a rusted out floor pan!!! I'm sure you"ll be pleased with the results!

I'm not familiair with Reflectix, but when I added a heat barrier to my interior, I put the new insulation over the original foam.  I figured it was more for noise suppression back ther than heat protection.  A lot more heat has to come in thru that big back window than from the floor.