I have recently been fortune it enough to purchase one of these Dnano vehicles but have some questions. (I received it with a broken rear suspension plate

so I have yet to try this sucker out)
I purchased the WRX STI chassis set 32301MB. Now, I see it comes with an Autoscale body complete with dummy chassis (O joy) as well as a "moving" chassis.
Now my confusion is, do I ALSO need to purchase one of these "Fitting parts set"? For an additional 40 bucks??? The box for the body DNX301MB does say that the "fitting parts set" DNP301 IS required to work with the "moving" chassis?? Or does my "moving" chassis already have these parts "fitted" because it came as part of 32301MB?
Can anyone shed some light on this one for me?