You're saying the law allows a touch screen to be used if it's secured with a "holder" but not if it's.... bolted to the console at the factory?

Why would that be banned? The wording talks about holding the device in the hand. I'm only talking about the recent UK phone law. Previously you could hand hold a phone as long as you weren't using it as a phone. It's now broader in terms of what the devices are, but still only applies to holding something in the hand.

Yes the law allows you to use navigation in your phone.