Will any motor work in a electric rc car?

Yes, you could use that motor. But you said you have a cheap 1/16th, meaning low quality??? If you get that motor for a low quality RC then chances are it will tear up the tranny gears. The Traxxas vehicle has stronger gears than the walmart and radio shack RC cars. So those gears can handle that kind of motor. You can get the traxxas motor to fit and work but I wouldn't expect your RC to last very long. Plus, the motor could burn up your ESC (electronic speed controller). You will notice a huge increase in performance but not for long because I would bet my left arm it will tear up your gearing before the battery dies. Hope this helps.