Two problems related to car stall have been reported for the 1999 Mercury Mystique. The most recently reported issues are listed below.
While driving at any speed, the vehicle stalled in traffic. The vehicle is currently at the dealer. The mechanic was unable to determine or duplicate the problem. The consumer talked to another consumer who experienced the same problem and the problem was with the module that controlled the computer module (possibly the ignition module) and a flight recorder was added and found the intermittent problem. (the problem hadn't been experience since per the consumer who experienced this same problem, not the consumer of this letter).
While driving at all speeds, the vehicle will stall, without warning. The consumer is having the ignition module replaced at her on expense, due to a similar problem that other models were experiencing, however consumer is not sure if the stalling problem is due to the faulty part.