I guess that I should have mentioned Home Depots' other options:
Reach Barrier Air Reflective Garage Door Insulation Kit-3009 at The Home Depot
Reach Barrier Silvertanium Garage Door Insulation Kit-3122 at The Home Depot
I did not mention them because I understood them even less, but it sounds like the same situation. So:
Reflectix 4 ft. x 25 ft. Double Reflective Insulation-BP48025 at The Home Depot and
Reflectix 2 ft. x 25 ft. Double Reflective Insulation-BP24025 at The Home Depot for $67.70, $2.25 less than a kit, of which I would need two.
Ryland, I have not ruled out the hinges, but at $83.94, I am not sure they would have the same ROI.
I wanted to do this while I have free time, before I am busy with school again.
I am not sure if the door is steel or aluminum, but it is metal.
I kind of mentioned that one and a half walls in the garage are not insulated. You just get the bats, staple them in place, and staple a vapor barrier over it? Is there anything wrong with using plywood instead of drywall? I just imagine plywood surviving better than drywall.