Keep any control wires (servo wires, antenna, ect.) away from power wires (battary wires, motor wires, ect.).
If you have a graphite chassis make sure that the antenna doesn't touch the chassis.
Don't mount the reciever on the servo.
Mount the reciever on two or three layers of servo tape.
Make sure that there are capacitors on your motor or the ones on the motor arn't damaged.
Check to make sure you don't have a smoked motor, running a car with a smoked motor can cause it to glitch.
Make sure there is not metal vibrating on metal, but since its an electric car I don't think there would be any, especially in a xxx-s.