There are two paths and both don't work anymore.

First is to bring the hardware and software design in-house. Except auto companies don't do well at software, they're used to letting OEM vendors write the engine control firmware etc etc. There's also the problem of the very long design cycles in car manufacturing. The new car platform being built today started its design four to five years ago. And that's when the hardware was locked down.

Volvo's platform was so old at launch that they threw in the towel and are now offering to upgrade your hardware if you complain hard enough.

The other choice is to shop it all out to a consulting firm or OEM vendor. Then you have cultural conflicts between the car maker and the programmers, communication overhead, choice of hardware conflicts, etc. And you know it's going to be shopped out to the cheapest bidder. And you're still at the mercy of launching with hardware that's way older than the smartphone in the driver's pocket.