blastfurnace wrote: No extra cost sounds like a good solution.
Would this allow music and/or phone through the iPhone. I would prefer to avoid a SD card (or USB stick) for music because I have apple music and you can't transfer music you don't own from the phone.
Only the Nav VI allows A2DP stereo music streaming via the GPS. The Nav V only has the Hands Free Profile. You will need to plug your iphone in via the USB port in the cubby hole (possibly needing an adapter cable) to play back via the bike speakers.
Otherwise you will need to pair the navigator and the phone to separate channels of a bluetooth headset. The best and latest BT headets (e.g. Sena 20S) now have automatic muting of the music by Sat Nav instructions. This has been a feature of the hard-wired (Luddites-only) Autocom systems for over 20 years.