Every class A I have owned-all gas- have not had insulation behind the top front cabinets. In summer with sun it gets very hot in the cabinets and most had electrical devices such as satellite control...
I used two layers of Reflextix in mine. It's flexible so I can form it to the shape of the front cap. Used double face tape behind it and aluminum tape along the edges.
Reflextix. Here it is at Lowes, but any home store or Amazon will carry it.
