The walls are 2x4 filled with cellulose and the attic has 10". Garage door has whatever they can put in them, probably thin Styrofoam. One small window and no other outside door. Correction, my area is 640 sq ft, not 460.
Thanks.
I have been searching and reading threads to learn about sizing and installing mini split systems. It has been very informative but I have found next to nothing about how to handle a hot car entering a well insulated garage. My V6 SUV produces a lot of heat and raises the garage temperature too...