I have changed the CPP for every part in a body, yet it wont change all the way. If i delete the body, the chassis moves better. Even with CanCollided off.
This script is in every part inside:
script.Parent.CustomPhyisicalProperties = PhysicalProperties.new(0,0,0,0,0)
It changes, but the weight doesnt. Even when doing it manually wont work.

2 comments
You can do
script.Parent.Massless = trueif u don't want it to weight 0.
thats what im going for, yet it still doesnt work