Originally Posted by
SatNav
Generally all the hop-up aluminium parts. Eg the MTF engine mount.
Mtf engine mount is a waste of money. When it was released, some drivers tested it without success, and went back to original mounts. Mtf mount simply decreases the grip of the car. Instead, Xray released a new one piece engine mount which would be a better option, but again, not really necessary.
Best option part investments would be lighter transmission parts made by Xray and CapricornRC.