What’s the killer app for head units that’s being ignored by car manufacturers?
Not applicable for this specific car, but I would really love a way that doesn't involve an ODBC dongle to monitor the nerdy battery details on electric cars. On extremely hot or cold days, battery temperature can make a huge difference in charge rate when you are on a road trip. And when I'm charging it's nice that most cars tell you the number of kilowatts you are receiving, but it would be nice to know exactly how many amps and volts as well.
I believe Tesla has an API that exposes some of those metrics.
Yes you can see all of these metrics and more on the Tesla mobile app. There's also a handful of 3rd party Tesla apps that do even more.
https://www.tessie.com/
https://tezlabapp.com
https://teslafi.com
Or host your own: https://github.com/adriankumpf/teslamate