When I bought my current car, I paid several hundred extra for the ability to parallel park itself, even though I knew I'd only use it about once a year. I just thought it would be a cool facility.
I mention this to illustrate how willing I was to spend money and get very little in return.
One of the most important features for me was a Sat Nav with realtime traffic information, as I would use this for every single journey I make. (I used to commute through central London and really, really, really wanted to optimise my journey time.)
I really, really wanted to have a built-in Sat Nav, as I hate having charging cable draped over the dashboard and devices planted there or on the windoe.
I concluded that no built-in Sat Nav was worth having, in fact despite costing hundreds/thousands of pounds extra, they simply could not do at all the job that Google Navigation on my Android phone did for free.
This was four years ago, things may have improved a little since then. But I still wouldn't pay for a built-in one. Google navigation is being improved all the time, why pay from something that is inferior to start with and won't be upgraded during the 15 year life of a car?