They all run the same darn bushing, 850, S70, S60, S80 and it is junk but it is the only thing available at the time. Get factory Volvo ones, Febi/Bilsteins, or Boge. When I purchase the Boges or the Febis you can see right on them where the Volvo name and number have been ground off, so they are the same thing. Either way, full hit on the darn things is only $35.00 each. The only thing you need replace is the upper spring seats, do them both and be done with it. If your struts are showing signs of wear, now is the time to do them as they will be out and there should be no additional labor to swap them at this time. In my shop I charge one hour labor per side and 1.5 hours for a 4-wheel align. The struts if they need replacing will set you back about $176.00 per side for factory struts. Last week when I was doing a set the factory Volvo struts were all that was available when I looked at 4 different vendors, this week they show Boges also. If you can get Boges for cheaper then do so as they are the same darn thing. Volvo struts typically go a long, long time but I have seen both struts and shocks in the S80's that were blown out entirely at less than 80K!!
To answer your question though, there really is no band-aid fix for your problem you will need to go in there and replace the spring seats or not. There is no half-way, kind of-sorta fix it deal on your situation. Real nice stuff these top of the line S80's that Volvo is putting out, huh?

Mark