Thanks to all who responded, i really appreciate that. I think I like the countersink idea and we will start just with paint for grass as he is only 5 and I want this to progress his way. Thanks again.

I was thinking of attaching my grandsons track to plywood by drilling a hole in the middle of the track and using flat head screws to hold it in place. Has anyone tried this and if so does it work. Thx