Correct, the purpose of the RC car mod was to indeed help my kids learn a bit about proportional control using parts I already have lying around the house, like re-using the Tx & Rx from a quadcopter we had built a few years ago. Guess I could use the ESCs and other parts as well from the quad we no longer use. Or just buy the few parts required to convert it to a proportional-control RTR car. Let's see.

Thanks all.