I am planning to do the same to my Bolt using 1/8 inch ABS and would appreciate any additional specific information you think would be helpful.Good thread with lots of interesting stuff.
One mod I did early on that helped performance (efficiency and acceleration at higher speeds) was reducing drag by completely modifying the underbody to make it completely smooth and cover up that huge rear parachute area under the hatch... It's held up to multiple top speed runs and its also held up through some horrible winter conditions which is a testament to its robustness.
Lots of info in this thread: https://www.chevybolt.org/forum/12-wheels-tires-brakes-suspension/8714-improving-drag-lowering-under-car-aero.html
Going to lighter wheel/tires was another one that helped acceleration and efficiency, but can hurt lateral accelration. However larger/wider isn't always better for lateral g's. I had posted acceleration data in another thread when doing those modifications. But here's an even better comparison of wheel/tire affects on acceleration, handling and mpg's: https://www.caranddriver.com/features/a15130598/upsized-wheels-tires/