Hello all on the Sprint 2 forum! I'm getting a hpi sprint 2 rtr-x 1969 mustang. I really love the look of the late sixtys mustangs, with that being said i'm already looking at hop-ups for this car ie: carbon chassis, carbon shock towers and i'm interested in the carbon upper chassis plate. Now this is where my questions come in. HPI states the upper carbon chassis plate requires use of a saddle pack, so does a saddle pack do anything for performance of this car? If not then is the upper carbon chassis worth buying? I read somewhere that the lower carbon chassis removes about 1/4 lb of weight, is this true? I guess I just want to know other than the upgrades that Marv has provided; is any of the other hpi upgrades worth purchasing. Let me know. I'll be watching this thread. Thanks!