It is totally an interesting topic, especially with more vehicles coming standard with auto-braking / steering / autopilot functions in addition to drive-by-wire, coupled with cellular / internet connectivity.
I definitely keep my eye out for this kind of thing - it really awakens my curiosity.
There is definitely a need for security, even basic security. Some of the transmissions from / to cars / datacenters were in plain text, and easy to decipher. They need to make it so that script kiddies / bad people can't just open a program and possibly cause cars to lose control.
On another level, what happens when cars are being marketed as "connected", but then in such case like the Leaf, where the system was never really kept up-to-date, and then taken offline indefinitely to fix the problem? Or what might happen if a company like Tesla, whose ability to push updates wirelessly is lauded, might need to be shut down?
Or perhaps in the not-too-distant future where a lot of cars are driving autonomously and might need to communicate with each other to take advantage of being close together for aerodynamics, or efficiently changing lanes, etc. What if their communications system needed to be shut down because of vulnerability.
I think not only should consumers factor that in to their decision, but also manufacturers have to weigh their liability to ensure their vehicles are controlled by whom needs to control them, and that the product they deliver is what was marketed.
Connected car control security hasn't been a huge topic, and I think it will greatly increase in the next couple of years.