Ads, of course, for some definition of 'works best' (extreme variant: self-driving car offers to pick up what you order while you are at work) If I were an employer, I might pay my personnel to have the infotainment part replaced by educational material on their way to work.

Nice idea...

As an employee you could get the ride in the car free, as a perk, iff you watch the educational material and pass a test on it. This would be assessed during the ride via onscreen multiple-choice questions; get less than 50% correct (or, turn it off) and you have to pay for the journey!

The crap they show in the back of NYC taxis does seem to fit the bill (short 2-3 min videos, changes fairly regularly, though heavily mixed with advertisements). It is crap, but I imagine once there are driverless cars, the format will gather interest from more creative sources.

Why use it for creative purposes when you can use it to show ads? Talk about a captive audience. I'm betting that Google is going so big into driverless cars so they can show you ads on the windshield once it's proven + accepted as safer than human drivers. It might take 20 years, but they're opening up a new advertising channel.

I always thought it would be cool to play an on-rails first person shooter where the "rails" matched the road you were travelling at the time.