I bought some Plasti Dip. It's made for putting rubber coatings on tool handles. If you thin it, you can also use it with a paint brush to coat plastic Transformer wheels. The end result looks pretty close to a rubber tire. But the real benefit is that it feels and acts like a rubber tire. I gave Bonecrusher a nice coating. With his new rubber traction, he is way more stable on his roller-skate feet. Since so many roller bots are coming out for RotF, I thought I'd post this.