One problem related to tank mounting has been reported for the 1998 Ford Contour. The most recently reported issues are listed below.
For several years vehicle made a bang when going over a speed bump just assumed it was bumper on suspension. Today I looked under vehicle found that the gas tank strap has completely rusted away and from the looks of it has been gone for a long time. The bang might have been the tank. Vehicle has been garaged with 61k.