I recently watched an off-road challenge on Speedvision. There were trucks, Dune Buggys, and 'other' vehicles which were modified for the mud, and everything. One thing that I was interested about were the tires of those vehicles.

Most of the competitors used their own customized tires. They were tires that had unique treds, and materials that they felt were best suited for on, and off-road conditions. But I have no idea of where to do such a thing.

Anti-Honda

 

from what I have seen, they take existing tires and just carve their own pattern with a sharp knife. So its not like they are melting and casting rubber into a custom one-off tire. You could do the same at home. Just make sure you balance afterwards.