You don't even need to make the punishment especially harsh.
What helps is to increase the likelihood you will actually get caught and face any consequence. It would be much better to reliably confiscate the cars of the people doing this than to randomly send a very small proportion of them to prison.
We have cameras, drones, police departments equipped with military gear, and software to monitor and record electronic communications.
The only thing missing is political will to make it a priority.