is it possible to play music through my phone to my disco without any invasive procedures such as a new head unit, such as through a special wire into the car? cheers.

 

You can buy a FM transmitter it plugs into the cigarette lighter, and then you can play Bluetooth off it. I have one I can charge my phone too, I really like the original look for the dash so I didn't want to modify it plus I'm not a big radio guy so upgrading to a better sound is not my priority. The transmitters are like $30 on amazon

 

The grom audio kit works well: https://gromaudio.com/store/bt3_adap...interface.html

 

The FM units work pretty well now.