Update: Good outcome (IMHO) on the heater box foam saga. I bought two kneeler pads on Ebay for a bargain £7.19
www.ebay.co.uk/itm/115792899002, they are made of some kind of light but dense black foam. I made a cardboard template to the size required, with the appropriate taper (by eyeballing along the underside and side of the bonnet). Using a very thin and sharp saw blade (aka a bread knife, as with cutting expanded polystyrene), the pieces turned out nicely. If you are really picky you can remove any saw blade marks by rubbing the pieces on a sheet of medium-grade sandpaper. I stuck them in place with good quality double-sided tape. The bonnets now pretty much touch the foam, and all seems fine on a drive out, so mission accomplished. (Oh and the unused mat now resides in my garden shed).
![[Linked Image]](https://www.tm-img.com/images/2024/07/13/1-Two-black-foam-kneeler-pads.jpg)
![[Linked Image]](https://www.tm-img.com/images/2024/07/13/2-Heater-box-foam-left-side.jpg)