Just picked up and in the process of building i tore a dust cover. Are they crucial? Should I go with Cav indoor setup or go by the box? Running all in doors on a tight track. And picked up the Tekin 8.5 pro combo. Good right? Never ran 2 wheel. And what's with the standard on the 1/10th scale and metric on the 1/8th scale? Now I need another set!