Toggling between autonomous control and radio control is much more complicated for the toy level car than for the hobby level car. Why? Toy level drives the steering servo and the wheel motor each with DC in both directions. This requires four wires. There is no common ground. Hobby level cars use pulse width modulation signals for these two jobs. Only two wires are required. The grounds are common.

Toggling between PIC and R/C in toy level requires switching eight wires - four from the radio receiver and four from the PIC. The same operation on PWM wires requires switching only two wires.

Hmmmmm...... That's a pretty good argument for sticking to the expensive machines.

Ken