Could you use some sort of rare earth magnet recessed into the ply and then the terrain could be modular as well? ( I do this on my table top gaming tables) just not sure if the magnets would hold up against the 1\24 jumping into them? If they do though that would be amazing!! I know on the tracks you buy its just pieces of foam that get propped up to make an incline, no?
You, my friend, are an ideas man. I have been racking my brain for ways to make the modular on modular idea for the jump/quarter pipe modules that I didn't want to be a fixed set-up.
The only potential issue I see it will the magnets be strong enough to attact the few steel parts in the cars and make them act funny as you drive over them (mess with the motor, suck the car down, inductive pick-up messing with electronics). I guess the only way to find is to buy some and test it.
I think the solution will be to come up with a system that allows the magnets to be removable but still be used a a fastener. Something to think about. I like this colaborative brainstorming stuff...thanks for your idea again!