[bigred90gt]

I has the same problem with my 90 GT. First, I put some foam weather stripping behind the liscense plate, because that was where the majority of the rattling comes from. That took it down a notch, but, it was still there. I finally realized that it was coming from where the spoiler bolted to the car. I had to take the spoiler loose, and put some of the foam weather stripping under it, then bolt it back down. It never rattled again. I would start with the liscense plate, then go from there. My 01 GT was an easy fix with just removing the plastic plate frame, and tightening the liscense plate down pretty tight.