I'm trying homemade lizard skin. I mixed ceramic micro spheres from amazon into 1 gallon of rustoleum, painting the floor from fire wall to back of rear seat. Some have used acrylic paint which is what lizard skin uses others have used an elastomeric like a butyl roof seal such as Kool seal. After this it will be a layer of frost king butyl duct wrap from Home Depot or carinsulation.com brand insulation not 100% set on that yet.
FYI google alternates to lizard skin. Jim