Yes, you will need a 3mm plate. Btw, I recently modded another Quark 125b without removing the motor wires. Once you have the top lid off and the front plastic off (power in side). You can use a small 3 inch long flat blade screwdriver. Slip it under the caps and gently pry between the aluminum spacer and the aluminum case. You will end up removing the insides and the rear plastic piece all at once. This way is much easier and cleaner without removing the motor wires. Let me know if this doesn't make sense.