Don't worry about the insulation, they all heat up in the front closet - just keep the door closed. As a matter of fact it is quiet possible that there is no insulation right behind the 'shoe rack' due to the lack of space. IMO a window awning over the rear window and over the window leading upstairs could be a big improvement. We had an additional roof vent with thermostat controlled fan installed at the factory to prevent heat buildup in the bedroom which helps tremendously - way better than running the AC all the time.
Congratulations to the Trilogy, you're going to looove it.
2013 RAM 3500 Dually Longhorn
2014 Trilogy 3650RL, W/D, Onan 5500, 8000# Axles, IS, 960 Watt Solar, 6x6 Volt Battery Bank, Freedom SW 3012 Inv/Charger