The car manufacturers just contract it out to companies like Johnson Controls, who make the system in my Mazda. It's running embedded linux and the interface is a bunch of javascript files. One of the bigger problems I see with this system is that Johnson Controls just doesn't give a shit about maintaining an old system unless a safety issue is presented. They're better off selling improved systems for use in newer model cars as a sales tactic. Android Auto/Apple carplay pretty much remove the ALWAYSBEIMPROVING component. Johnson Controls could pretty much just sell the same head unit/LCD combo for the next 10 years and no one would notice.

I build car dashboard software. You are right. The SW is shit. Exceptions, from what i've head are Volvo and Daimler. Don't know the kind of resources Tesla puts into their SW and am not sure if it's not just hype.

Even in the Model S, I use my phone's directions. Tesla's map app is great, and the UI is _really_ good (even better in the latest update!), but their source for navigation is garbage (and also their routing algorithm).

I hear it's cause whatever they use works offline, but also because Google wants them to send back real time data, but Tesla doesn't want to (forgot where I heard this though).

I would much much prefer to use the Tesla UI for nav, but the directions are really that bad.