I've been using the Tom Tom Go App on my iPhone with wireless Car Play to my PCM 6.
I plan the route using Google Maps then using this conversion tool
Maps to GPX I convert the route to a GPX file which I then import to TomTom My Drive
https://mydrive.tomtom.com/en_gb/#mode=viewport+viewport=51.58004,-2.05969,13,0,-0+ver=3 from there I sync the routes with the TomTom Go App.
The conversion step can be missed out by planning the route directly in TomTom My Drive if preferred.
It works really well and unlike using Google Maps does not need an internet connection as the maps are pre-downloaded into the iPhone, Traffic information is included and Speed Camera locations with warnings are also shown if that option is selected.
The App can be downloaded with a free trial and then there are various subscription plans, mine is £19.99 for 12 months.
I have used it successfully on two Porsche Club trips and have just used it to plan a European Trip that I'll be doing in a couple of weeks time, it makes any of the Porsche Navigation systems (I've had them all from PCM 3 to PCM 6) look prehistoric.
The App can be downloaded with a free trial and then there are various subscription plans, mine is £19.99 for 12 months.