one of the limitation or concerns with Amphicar is rear seat leg room. Has anybody ever made adjustment to this? I have seen that Disney has modified their cars back 3" on just the base cushion. My ruff estimate is a 6" rearward adjustment to the seat base front bulkhead and a 3" rearward modification to seat back could be made without crazy mods. Any thoughts? I'm hoping to complete before Florida swim-in, I might have a full crew onboard and no fun sitting sideways in the back.