Hi, well I will just make you know why I'm the best option for you:
First becouse I'm a lover of R/C cars.
Second couse I have lots of experience related with motorsports, like a designer, or improver... also with plastic parts, so I recommed you the injection plastic moulding method instead of cnc machining.
Resulting parts will be cheaper if you have plans to fabricate in serial.
Third: There are some iimportant things that you must take care when design a plastic part for injection moulding, like be thinking on the fabrication method, if not you can design a part impossible to fabricate. I allways look for the better performance.
Fourth: If you tell me about what kind of plastic will you use for that, I can use the finite element analisys once the 3D model is done. Then I can get a better resistant wheel design, or lighter one, or the combination of both. If you don't know it exactly also I can help you to choice.
Hope we'll work together on that project.
Best Regards.