One problem related to rear suspension leaf spring has been reported for the 1998 Ford Windstar. The most recently reported issues are listed below.
This failure would have resulted in a rollover if the broken spring had ruptured the tire. The spring stopped just short of contacting the tire. There are scuff marks, but not to where the tire needs replaced. I have the original coil springs for analysis if required. ( both were replaced after the incident. ).