Originally posted by RacerTex
Also, remember that their contracts probably have that written in. Only AE issued materials on the car - unlike HPI which it seems have given Atsushi Hara the lattitude to modify the Pro3 until it's not really a Pro3 anymore. 
Personally, sometimes I use a common composite chassis. In fact now I have 1 1/2 cars one with the stiff and light graphite chassis and other with the composite chassis (one has the red reedy sticker (graphite) and the other has the green sticker (composite)). Sometimes my buddies jokes with me what chassis should I run today (but, on the track I grease them a lot...
)
Sometimes the composite helps to have more grip on some tracks. I wouldn't mind using other than stock chassis.