Over on YouTube user SilverXiaify has uploaded a video of a project he completed for a class in his electrical engineering school. His project involves controlling a remote controlled car using a ham radio. The remote control car carries on board an RTL-SDR for signal reception and an Raspberry Pi for data processing and control. The communications protocol they used is a naive version of AFSK700.
On YouTube user 王康 has been working with his HackRF One to create a computer keyboard controlled interface for his remote control car. The HackRF is a ~$300 software defined radio similar to the RTL-SDR, but with transmit capabilities.
To control the car he wrote a GNU Radio program to generate a control signal that is transmitted by the HackRF and a GUI to listen to keyboard presses on the PC.