Two problems related to rear suspension have been reported for the 1999 Mercury Grand Marquis. The most recently reported issues are listed below.
Rear end of car skips sideways when hole or bump hit or uneven road at freeway speed, causes great concern as driver really does not have control of vehicle for that duration. Potential danger of contact with other vehicles at freeway speeds.
Rear of car jumps sideways when tire hits manhole covers or pot holes. Problem is same as previous 98 g. Marq. @ 65-70 mph this is quite dangerous, other owners have same problem.