I know this is an old post but browsing through! I had a similar issue with my V70. It turned out to be the rear tailgate connection loom in the headliner at the rear. To access this I removed the rear light, and then an 8mm bolt. Headliner then pulled down (with clips) and I was able to access the ...

If you have an AUX port (which I think you will at the age of the car) you can easily add a Bluetooth receiver. There’s loads on eBay/Amazon. It’s the easiest and cheapest way of adding music streaming. I would try and find one without hands free personally so there’s no fighting over your existing ...