I run the RB5 on indoor carpet tracks. I'm no top class driver, but I had some good results with a 12x1 V2. Expect to be the odd one out. If you can live with that, you will have plenty of fun with the car. It reacts crisp and clear on setup changes.
I did not break anything yet, so the spares box still well-stocked
I have to disagree with Sparrow, as spares are easily available directly from Kyosho Germany. Most parts cost very little (with a few exceptions).
Have a look. Ain't it beautiful? 