Missed the insulbright. I've been using windshield reflectors for years.

Several "relief cuts" in the blue foam cylinder may end the tension that is trying to straighten the pad. If you still have the blue cozy, it might be worth a try. I'm thinking cuts on the inside, if from a saw blade, might allow room for the pad to close on itself and mostly fill the voids. Knife cuts on the outside shouldn't remove any significant amount of material and just allow the foam to stretch into a circle.

Good Luck!

CM