I have a 1993 Mercury Sable GS and it has about 92,000 miles on it. It sat for approx 2 years when my grandmother passed away. When I took posession of it 3 years ago I noticed a loud hum when driving coming from the rear. To me it sounded like bad wheel bearings but I can not find anything on here about the car even having rear wheel bearings. The hum is still there and drives fine. Its just loud and annoying. I have drum brakes in the rear if that helps.