What about either of these:
Not plastic, but not glass, some type of wood fibre like board.
http://www.fastrax-rc.com/Fastrax-Me...d?search=board
http://www.fastrax-rc.com/Fastrax-La...d?search=board
I've found the medium one a little tight for 1/10 scale.
If you have the room the large one would be the one to go for.
Any where that stock CML products (Team Associated etc.) should be able to get you one.
MiCk B. :-)