So you're basically arguing for an Android-esque project for cars, where Samsung or Ford basically fills the device with crapware and bloat over a simple base s

So you're basically arguing for an Android-esque project for cars, where Samsung or Ford basically fills the device with crapware and bloat over a simple base system? I'd be fine with that, as long as there were firmware signing mechanisms in place to prevent every 16 year old with a USB cable and a penchant for speed from modding the family car. Early Android ROMs were a lesson in how not to modify things; luckily there wasn't a lot of widespread damage done with the quantity of compiled binaries of unknown origin being distributed over typical filesharing sites like Mediafire.