One problem related to front suspension springs has been reported for the 1999 Mercury Sable. The most recently reported issues are listed below.
There were no events leading up to the failure. Coil spring failed and broke going out of our driveway, puncturing inner side wall of front left tire. We got a replacement strut and coil spring assembly from a salvage yard costing $53. 30. New tire costing $59. 73. Old coil spring showed no signs of abnormal corrosion so it should not have failed. We still have all old parts.