I just want one thing: A place to plug in my smartphone or tablet via HDMI, USB, and a four-pin 1/8" miniplug for audio in and out. And I want the results to be that my phone shows up on a self-hiding touch display on my dashboard. It's a moderately expensive way to handle the device mounting problem, but it's also completely future-proof and the user can install anything they like, whether it's meant to be a portable device or not.
A manufacturer could reasonably implement this without losing money if they simply made entertainment a standard feature. There's no worry you'll skip the option if it's not optional. And if they just partner with someone else to handle GPS updates (tomtom? whoever) then they don't really have a revenue stream to lose there. Selling GPS updates is probably not all that profitable for most automakers, but I have no figures.