You could always put a 3/4" or 1" inch rigid foam board from Lowes or HD on top of the plywood with construction adhesive. Tape any seams and then paint earth brown and, while still wet, sprinkle with green and yellow fine turf and when dry, spray the turf with a high hold hair spray - instant layout. Roads and streets can be masked off with duct tape before painting and go back with flat black or silver concrete paint. The foam holds accessories very well.
