Super pissed with Trinity and Tower Hobbies. My D4 had a DOA sensor board. They sent me another which took a week to get. I finally get to test it yesterday, and I put in a high torque certified rotor. Car gets a half lap in, motor makes a loud siren noise and smokes. Tower could care less, and Trinity is blaming bad solder joints even though they haven't seen the motor. So much fun to be out 150 bucks without anyone caring at all.