Front edge I cut from foam but it upside-down.



Rear foam and its upside-down also



After cutting foam and inserted into opening. Still 3" of foam in middle but only 2" above wood base.

I didn't realise you had cut out so much of the foam, I didn't do that, I just cut the square out or the seat base and fitted the plate directly to it in the belief that the foam would sink into the plate. It hasn't had the desired effect, there is a bit of difference but not as much as I'd hoped. I haven't driven it yet so it might sink a bit more as the landy bounces along, if not, I'll remove some of the foam as you have done. Thanks for the guidance, I appreciate it.

Col