It costs $2,500 to unlock this new software feature.
That is not (entirely) accurate. The autopilot feature is currently on the price list as a $2500 option. I'm under the impression that all current cars _may_ have the right sensors (they are generally helpful in getting good collision avoidance ratings--I'm not sure but I assume if you have the hardware and you did _not_ pay for autopilot when it was available as an option, then you may be able to pay now to enable the feature).
However, my car, built in late September, 2014, was not priced under the current pricing model--there was no autopilot option at that time, yet my car (like most cars built in late September, 2014) has all the sensors and autopilot is fully enabled on my vehicle as of the software update I installed this morning. I did pay for other options that are no longer available (as I recall, parking sensors and fog lights), but I did not have to pay $2500 to enable autopilot. -se