...and relatively cool looking too, if painted or logos added
Anyway, go to a hobby or craft store, and buy strips of balsa wood. Get 1/4" x 1/8", and they come in something like 32" lengths. This works especially well for anyone using any kind of foam track base. Now, buy a pack of pins (from a sewing dept). You can easily stab the pins through the balsa wood, and it flexes quite well too. I put the pins about every 1 1/2 to 2 inches. I stuck it into the foam I have (no real track layout just yet) But I think it works well. Crashing right into it, this system flexes, and rebounds the car, and if you rub against it in a turn, you can still cruise right along really. This way, for anyone who changes they're setup, or has to break it down for storage, its really easy to install or change!! I have mine stuck in down to about just about bumper height on my bullet clone (the zip is apart, w.i.p.)
Anyway, just some food for thought for anyone!