Front and rear tires primed.
By far the most challenging part of this entire build and the one key design feature that sets this build apart from other builds (which tend to use the tires that come with the Tamiya kit) . The tires and their tread were designed by me after I taught myself to learn Rhino modelling software, then 3D printed via Shapeways in New York, using Frosted Ultra Detail.
Basically there are three parts to each tire, one complete outer ring and two sidewalls. Note the tire rims are from the Tamiya kit and weren't 3D printed. In order to get a very snug fit with the rims, I cut the sidewalls with a razor saw and slotted them into the rims, then repaired the area where I sawed through the sidewalls.