That’s the intent, at least:

Are you intending to ship a (close to) mainline kernel, or a Board Support Package (BSP)/vendor kernel and make it work with a libhybris/Halium approach?

We’ll go with bare-metal Linux—no Halium, no libhybris. We want to stay as close to mainline as possible and actively contribute upstream.

(I haven’t really used them a lot in the heat yet) Last enclosure was ASA, but AFAIK, black ABS is OK too because black pigment absorbs most of the light/UV, preventing plastic from degrading as fast

For offline navigation on Linux, have you looked at osmin? It was pretty decent on a PinePhone.

How do you handle power-off? Does Raspberry Pi just shut down? My thoughts were to use Alpine or some RAM-based OS that would not corrupt SD card or the hard drive.

I have been messing around with building an in-car navigation from e-waste for a while now. Right now, I settled on an old smartphone with OsmAnd and wrote my own app to view the reverse camera.

.NET applications using .NET Core or later are intended to be cross-platform, so technically, Linux can run .NET apps. (The use-case I know is running .NET sites on Linux servers)