One thing i did not mention in my last post was that I tried my home brew F1R style top deck. I made it from some fake graphite- basically 3mm fiberglass with a graphite veneer on each side. I have a big sheet of it laying around, so it was fine for this. There are 2 extra holes in the original Exotek chassis, so I also incorporated these into my upper deck so there could be the choice of 2 or 4 posts on the car.
Running the car last night, it was traction rolling, so I wound up putting the full long upper deck back on to make sure that the cause of the traction rolling was not the chassis stiffness. I do think that this sort of thing will be great for lower traction racing like asphalt.