Like most of you, I use a lot of electronics, especially when we snowbird.
In our 37FB the entertainment center is over the fireplace in the opposing slide out across from our recliners. The doors to the entertainment center are made of plexiglas. I have a router, printer, Tivo, digital adapter, Ooma, stereo receiver and cordless phone base in the compartments. Needless to say, heat is a problem.
At first I just left the doors cracked open and resting on their latches. But the heat caused problems for me stereo. I considered replacing the plexiglas with metal screen, but it was too uneven and didn't play well.
I did find replacement airconditioner filter material at Lowes for $1.97. The material is easily stretched and almost the same shade as the plexiglas. The size is perfect for the replacement. The plexiglas is removed by pulling the plastic wedges from the door. Laying the filter material over the opening, and starting with the longer wedges first, I installed the filters.
Heat is no longer an issue and according to 'she who must be obeyed', they don't look half bad either. Here's a pic.
2017 CC38EL Silverado 3500HD