I have a 2010 S80 with poor radio reception. I've seen posts regarding suggestions to help cure the problem, namely a) install a new amplifier, b) install a brass strip to hold the coax connector in place, c) install a grounding wire, and d) turn the rear defrost button on/off several times.

I've removed the rear panel above the back seat on the drivers side behind the rear door-it just pops off and exposes the amplifier and connections. I've wiggled all the connections and they seem secure. I don't see any coax connectors as mentioned in some of the posts.

I've enclosed a picture I took of this area and would appreciate any comments on what the problem or fix might be.

 

Since no one else is commenting, and I am one of those who has posted about the use of the brass strip, I thought I'd chime in.
I believe the brass strip is only useful for '06 and older cars, after that the cars were made without the coax, as you have discovered.
Still, the principle of a poor connection is likely the root cause. Start unplugging things until you lose reception altogether, then spray that connection with contact cleaner and follow it as much as possible, cleaning succeeding connections. Might work, it's what i would try at any rate.
DON"T waste time and look like a monkey locking/unlocking doors, flicking your high beams on and off, or turning on your emergency flashers on while standing on your head in the drivers seat with your feet extending through the sunroof,

 

Makes sense. Only one of Volvo’s several issues.