tram

Yes sorry been at work. If you remove the heater controls, a guide to which is found on the up forum under changing the fascia, it comes loose and behind is a plug which has numbers on, the 5th is what I used to power stereo . it's the thickest and on the left as you look at it. It seems it might be ok even with start stop it may have been my settings on the stereo itself. It didn't turn off during start stop today so that wire seems to do the job.

If you don't have stop start you'll be fine with the wire #5 from the heater then as that's ignition dependent! And easy ish to get to and piggy back

Don't use the wire for pin 5 in the back of the heater controls if you have stop start as this goes off when engine stops. Much to my annoyance when I changed the radio, still need to find an ignition controlled power wire....