Depends on the car brand. Some kept their dependance on software quite low like Mazda. Some decided to take a risk with the software gods and tie their entire functionality to it while simultaneously laying off good workers and rehiring the lowest bidder.
The worst bug I had on my car had the onboard computer not starting, and the screen remaining black. It meant I had: no GPS, no music, no backup camera, and no parking sensor.
But apart from that, the car was driving perfectly normal, and all the other features were working as expected.