Thanks for the above - for some, as yet unexplained reason - my phone worked perfectly as of yesterday - as in, I tried to make a call - and had the handset to my ear (my gf was drving...) and the call went through the car’s system with the phone connected...

Think this is genuinely the most unhelpful post I’ve ever made in about 20 years across various car forums: I had a problem. Problem is now resolved. Have ABSOLUTELY no idea why it now works!

Thanks for input to those above though - my only half guess is that perhaps it was battery related? My phone had 100% charge - and the car had been on some long journeys and so had also been charged - whereas a few weeks ago we had a strange incident where the alarm went off as we drove along for a about 10 minutes, and had been on a few short journeys that month without a long run to charge the battery... - so had put it down to a weak car battery... (am grasping at straws for an explanation here...!).