Well...you can find out it is the rear seal at $500+ and because it's a slow leak, put it off and then do what we did to my daughter's 1998 S70...my husband put oil in her car before she went on a road trip and left off the cap. Of course, after 3 hours of driving, the oil all bubbled and splattered out and the engine/oil lights came on and the gas pedal started rattling. So I've got a blonde 18 yr old sitting on the side of the highway with her broken down black volvo. It is now sitting in another state at a closed repair shop that doesn't specialize in volvo's. The vehicle will not even start at this point. So, now we've got more than a $500 bill waiting for us and unless I can get it "retowed" to a volvo-savy repair shop, I might as well just junk it and buy her another...