The hpi nitro mt isnt really race legal. Roar has a class for it but not many people run 4wd stadium trucks. Unless your track will let you run the 4wd with the 2wd, I would think about saving for a 2wd st if you are really interested in racing. You could also try to start a 4wd st class of your own, you would probably need to find atleast 8 people who would be interested in running them.