you can find ABS in a local hardware store such as home depo (find the pvc and the black stuff next to it is abs it really isn't that hard)
and sry that I haven't checked the forums in a while I just bought a new airbrush and painted my first body

and to answer the question of how we cut the abs
LivingLegend has a workshop so we used his horizontal bandsaw to rough cut the size then we threw em on a metal lathe to get it down to the exact width
and depending on the wheels you have you might need to sand down the edges, the hpi ones I got we had to lathe down a little bit to make it fit in the ABS but the wheels that came with my TT-01 slid in and fit quite snug

and to quickly explain offset it is basically the position of the surface that comes in contact with the hub of the car from the center of the wheel's width
for example the rims I just ordered for my 85 Toyota Corolla GTS hatch are Work Equip 03's 15x8 0 offset
15 is the size in inches of the rim 8 is the width in inches and the offsett is how many mm the portion of the wheel that comes in contact with the hub is from the center
15x8 -15 offset means that the wheel will mount to the car 15mm twards the back of the rim and give you more dish but will may cause fitment problems
15x8 +40 is a fwd offset and means that the wheel will mount 40mm closer to the front of the rim
it all figures out to around 3in of polished lip but doesn't change the fact that i've been waiting 3 weeks and still have to wait for another 3-5 before I get them


and its kinda late so sry if I got anything wrong