I just sent an e-mail to a couple Tamiya Racers and Tamiya dealers asking them for those exact changes as on Surikarn's car. My opinions on the car are:
1. Thicker top plate or chassis or both, but heavily milled to save weight.
2. Diff cases made out of Hard Material.
3. Bukhead to tie shock towers into chassis for added stiffness and consistent handling (Maybe hard material for diff cases will be enough).
4. Redesign of front gear and shims included in kits to shim crown gear.
5. Wider front bumper for racing indoors.