Folding layouts are possible, but I fear your size of 8' x 4' would need a double fold
to get into a car/estate although I've considered the possibilities I decide it would not
be reliable.
What I have done is to use a 6' x 3' format where the two halves of a clam-shell close
to fully protect the track and basic layout scenery. You will find a picture heavy build here :-
viewtopic.php?f=22&t=32187A double fold would have trackwork on the outside on one segment where it would be
highly vulnerable to accidental damage, particularly when in transit.
My two 'Thomas' layouts have done many, many exhibitions. The first, as in that link is
still used by the Silver Fox DCC club in Milton Keynes and my later build down here in
Dorset has done 34 exhibitions to date without problems.
Geoff T.