Speaking of the interior camera, the more I think about it, the more possibilities I realize that you could do with it. Two new ones that occurred to me today:
* Gesture interface. For people who complain about "having to use a touchscreen", and don't think voice commands are good enough - just wave your hands in the air to change settings.
* Video conferencing. You already have a screen, after all.
This is in addition to all of the past things, like driver attention monitoring; monitoring of children / other non-owners granted permission to drive / ride in the car; theft prevention; etc.
You know, driver attention monitoring is a whole bag on its own. E.g.:
* Audio alerts if the driver starts to doze off. If they don't respond, slow down, pull over and put the hazards on.
* Don't let the driver go too long without looking at the road when Autopilot is on.
* If driver is being inattentive with autopilot on, make autopilot more sensitive. If it's not sure whether something is dangerous, and the driver's not watching, it should assume it's dangerous.