It might be easier than you would think. It's possible Tesla (or other vehicles with self-driving features) have latent capabilities already in their software,

It might be easier than you would think. It's possible Tesla (or other vehicles with self-driving features) have latent capabilities already in their software, which just need to be switched on. A hacker playing around in his garage might feasibly jailbreak the car and flip this switch. Whereas I would agree with you to the extent that writing self-driving software that uses all the various data inputs and maps to pilot the vehicle, from scratch, is not something very many people are even capable of doing.