I've had machined a custom set of weights that fit in the chassis slots total weight is around 87grms these are made up of 3 different pieces and fit under the Lipo's the no modification other than removing the foam strips
CLICKY
Secondly we have had CNC Machined rear alloy bulkhead made, this has a quick release ball joint hanger so you have no need to strip down the rear of the car just to adjust the ball link position CLICKY
and last but buy no means least
The front wishbone brace cnc machined from t6 alloy we haven't managed to bend one of these yet unlike the original ones CLICKY