the main thing in insulation is heat migration. many of these products after a while driving will heat soak . meaning the inside will be the same temp as the outside. building products belong in your house . not your car. i have used lizardskin for a long time and am very pleased with the way it performs. keep in mind any petroleum product will melt and or burn.
the 56 big window i finished last year had lizardskin sound control and heat control. i test drove it for around 100 miles before upholstery. the floor was only mildly warm. and this was july. i'm still waiting for some of these home brews to get finished and on the road .