Rock crawlin inside

[mazdaparts]

For my VMG training course I used some spray foam insulation. I was sealing a few air gaps and had about 2/3rds of a can left. You can't reuse this stuff very easily so I too a big piece of cardboard and just started making some rock like shapes and some log like shapes on the cardboard. After it hardened I tried it out. Worked great. Only problem is I didn't seal it or anything and if you spin a tire it can and will eat into the foam.