I'm thinking something like this might work. I need to get the grill from my RV for accurate dimensions and I plan to 3D print it in PETG. I'll post back here if I have any sucess. Drawing below is very rough draft. I'll need to go through a few prototypes to get it how I want.
The rubber feet have to be the worst design ever. I loose at least 2 hauling out of the RV storage area.