If you want to put material on the perimeter of the track to protect your car there are several alternatives.
One, you can buy 4-6" piping insuation (FOAM) and that works GREAT. It comes in different lenghts from 2 to 8 feet. It will absorb the shock without damaging the car and you can shape it any way with duct tape. YOU also use duct tape to adhere the foam to the carpet.
Another solution is vinyl/rubber elevator/stair railing. YOu can get it at any building supply house. You want to fold and wrap to define your track perimeter. Again, this will absorb energy w/o causing damage... YOu can use duct tape or tie wraps to fold the molding and get the shape you want.
There are other solutions but these are easy to obtain and work great.
If you need more help just ask...