Thanks to all for the help on this thread. I really appreciate it!
I bought this unit and installed it...
https://www.aliexpress.com/item/And...32717691300.html?spm=a2g0s.9042311.0.0.lrsyus
Ask the chap to ship from Germany if you're in the UK! I think its about £10 more but no probs with tax.
Shipping took about 10 days.
Easy to install! Took me 15min. Checking/configuring/testing took me a couple of hours without faults.
1. Remove negative connection to car battery
2. slide out existing radio using 2 pin removal tool (can be bought from Halfords)
3. Unplug the electrical cables
4. Plug cables into new unit (see detailed steps for GPS below)
5. Connect negative to battery
6. Start car and check working (checks: radio, dvd, Bluetooth to phone, gps detected, steering wheel controls....)
You will need to reset car clock, date, ect....
The radio on the new headunit works much better than the standard unit in my 159!
GPS good but iGo software is a bit rubbish - this is a matter of choice.
Bluetooth for voice calling and streaming music from phone is excellent. Call quality perfect on both sides of the call. WhatsApp calls perfect too.
Controls on steering wheel perfect.
7. When happy, slide unit back into place.
**GPS***
I placed the GPS receiver in the roof cavity just above the passenger pillar.
1. Pull off the covering over the pillar. May need a blunt implement if fingers not strong enough.
2. Pull the ceiling covering away slightly and pop in the receiver the correct way up (side that says GPS) facing upwards towards the sky and in contact with the metal roof.
3. Run the chord down the pillar and then slide/wedge into the rubber seal at the bottom by the dash.
4. Remove the plastic panel that has the key for the passenger airbag. Run the cable through this and then into the glovebox. (The cable in the glovebox is the only visible cable in my setup)
5. You should find an opening on the right of the glovebox where I pushed the cable into the space behind the headunit.
6. Connect cable to headunit.
Hope this helps.