New for the Serpent 4X comes this double vertical top-deck and top-deck stiffeners. The new top-deck is the base for all the new flex options and it consists of two equal shaped vertical oriented 2.5mm carbon fibre plates. The plates are connected to the front and rear suspension with a machined aluminium adaptor plate and unlike flat top-decks, the vertical oriented double top-deck still allows for a lot of linear torsional flex, but basically eliminates any longitudinal tweaking and reduces torsional tweak drastically. It can be run in addition to the kit aluminium centre stiffener. The H-shaped stiffener plate can be removed when the top-deck is used to create more flex in the front and rear section of the car. To stiffen up the assembly further, there are two top-deck stiffeners available which connect the vertical double top-deck to the centre stiffener/motor mount assembly. Both can be used individually, to tune front and rear flex individually.