One problem related to ignition module has been reported for the 1998 Mercury Mystique. The most recently reported issues are listed below.
The vehicle stalled2 blocks from home in am. It was able to be restarted, but died when put in gear. It was towed to the dealer. They were not able to duplicate the condition, but found a TSB that stated to reprogram the pcm. They said this was not covered by the extended warranty. I contacted Ford customer service, but have not received a reply. Ford announced the other day that reimbursement for repairs to their vehicles that stalled without warning. This vehicle falls under that condition. I feel this condition is very dangerous, since the vehicle stalls without warning, and all power is lost.