Normally, RC cars can't roll free, when an electric motor is off, due to reduction inside the motor.
As a result - no free rolling, no inertia. Sudden starting and stopping. Robotic movement.
In my RC car a clutch is automatically enabling/disabling, once the motor is on/off respectively.
It's similar to a real life driving, where you can alternate acceleration and free rolling in a neutral gear.
1 PF L-motor for propulsion
1 PF Servo-motor for steering
https://youtu.be/HMyCtJ3kZMM
https://www.instagram.com/parazels83