I had a similar problem and found it was the door wiring loom had a break right where the door hinge is try to remove the rubber cover over the loom and check for breaks in the wires soldered mine up and all works fine now
Glad you've found this post useful 🙂 I personally haven't used the Bluetooth products so can't recommend any unfortunately. My advice would be to Google them and look at the reviews.
Cheers
Steve