So, what do you expect from your rig AC? We have a 13k BTU AC in the front/master and a 15k BTU in the living. At present, the main 15k AC is keeping the rig at 10-12 degrees lower than the outside...
We bought rolls of quilted foil insulation at Home Depot and put that in our windshield and windows when we are in high temperature areas. Get the 4x10 rolls. Also if you have skylights and vents cover those too.