This isn't good for the top of the heater box and it's even worse for those small parts that can roll of into some under-bonnet nether region. Our tray is made from the same nearly indestructible vinyl that long-haul truckers use to tarp their loads. A layer of soft foam protects the heater box and a large lip contains tools and parts. Magnets keep the tray in place. Made for you in the XKs Unlimited Upholstery Shop.