I'll probably go with something from oxygensensors.com or call Steve at Tousley Ford - they have great pricing there!
'98 Mystique Zetec w/ auto trans
103,900 miles
Kenwood KDC-MPV7017 CD/MP3 HU
Kenwood KFC-6889ie 6x8" 3-way speakers
'96 Mystique Zetec ATX
108,000 miles