[BAracer]

I'm beginning to think that an 8x4 set up perhaps isn't as portable as I am imagining it would be, so another idea...

There is space in the garage to fit an 8x4 table unit like this: -

   

on which I could set up a Scalextric track on an adhoc basis as required. Between those times, it could be the base unit for a separate MDF sheet that would be the learning exercise for a routed track.

There is a solution somewhere in all of this!