As Steve has said, the law is confused.
The Law was written to stop the use of a mobile phone for any purpose that involved holding and touching it. This was drafted before phones did duty as a Sat Nav or music source.
I understand that it is legal to use a built in touch screen for any purpose, including making a call, and to touch a dedicated sat nav on a mount. But both are not recommended. But not a device that is also capable of making and sending text messages and phone calls.
