My driver's seat is too soft, hence painful on long trips. Until I took my Ford Expedition on a 7 hour trip with only one brief stop and realized when I arrived that I felt no pain, I figured I was the problem. Now I know it is the seat. Bought car new, weigh 170lbs, 5'10" - how can I get the seat cushion firmer? My guarantee runs out soon and I have an upcoming 4,000 mile trip, and I'd rather drive the Volvo but need to do something to the seat in the next week or two. I actually don't think that it has deteriorated from when it was new, rather that it was just always too soft. My wife's 2000 V70 is also too soft. Has anyone else tried to fix this from underneath without taking the upholstery off? Did it work? Is there a dealer fix?