+1
If your making chassis, shock towers, pod plates, etc. you want to make sure you buy the right stuff. The standard material used in the RC industry for cars is Quasi-isotropic plain weave pressed material. Typically it comes in 2mm, 2.5mm, 3mm, 4mm and custom thicknesses. The material is made up unidirectional carbon fiber sheets arranged at 0 degrees, +45d, -45d, and 90d with a top and bottom layer of plain weave. The material is pressed at greater than 200psi and cured. The end result is semi/gloss finish and a material that bends the same in all directions. The material machines excellent with very good edges. Check out
http://www.kcinc.com/solidpanels.htm for more info. KCI's prices are less than half per square foot than anyone I have seen and the material is top notch. I have heard of some people using bi-directional plain weave to vary chassis torsional stiffness.
High gloss twill single and double sided. The material is very pretty but bends differently in either direction. This material is typically layed up by vacuum bagging on glass at one atmosphere (14psi). The end result is beautiful but not very good for chassis or structural RC car parts. Machinability varies from good to a real pain in the ass. This stuff tends to fray easier and produce high and low spots on the edges as you machine across the grain. The double sided stuff is usually two sheets bonded together and not good for RC. I have also machined other vacuum bagged material with satin finish, rough finish, and multiple different weaves. They each have their own machining characteristics but for the most part machine about the same.
In general for RC cars avoid any material that is not pressed. I machine about 40,000 parts a year out of FR4/G10 and carbon fiber. The biggest challenges I face are getting a consistently good cut with vacuum bagged material especially thicker twill sheets (1mm+). G10 and Quasi are relatively easy.