> I'll have my car a lot longer than I have my phone

Doesn't that make CarPlay/Android Auto a good thing? Provided the car supports both platforms, it means you can change phones during your car's lifespan without having to worry about losing features, and you get new phones as your phone upgrades without having to change your car.

I don't know, what if a third mobile OS is developed and gains traction (or is just one that I prefer) but it isn't supported by the car. What if future releases of iOS or Android are incompatible with a 10-year-old version of CarPlay or Android Auto?

I'd just prefer to minimize dependencies.

CarPlay and Android Auto were engineered from the start to be as agnostic to the car's hardware as possible. Your car's stereo is really just a dumb screen (i.e. just a display and input/output interface) with the phone doing most of the rendering + a few other things (i.e. providing some car instrumentation, like fuel remaining, if the manufacturer enables it) - the hardware requirements aren't really strict from a performance standpoint (minus CarPlay Ultra, and even then, that's just a tighter integration).

There aren't any. Just don't use carplay/android auto and you just have the manufacturer supplied interface.

That's true, as long as they give me an aux port.

Kind of a waste of the nice big screen built into the car, then. Are you just going to use it as a backup camera?