My dashboard flew through the IVA with no foam. You don't need foam if its radiused. I have 12mm MDF, ran a router around the edges to give the 6mm radius, then stuck some pipe on the bottom edge (40mm diameter) to give my 19mm radius. Personally I think foaming is tricky to give a good finish. Looks bubbly and uneven.

I could do with recovering my dash as it has a couple of battle scars where the dash mounted tax disk holder used to be on the passenger side. Its also an opportunity to change from black to red.

Theres a variety of leatherette available on Ebay, what have people found is the best stuff for dashboards, canvas backed or cotton backed, normal or extra thick ?