Beazle

Seeing how it still vibrates when the engine is low in revs then it most likely is not the motor mounts. I have noticed that the control arm busings go bad on these cars. When the control arm bushings go bad it allows a vibration. Someone feel free to back me up or say I'm full of it.

I had the same problem on both seats when I purchased my SC ('93). I took the seats out and found out a "cap" came off where the torque from the motors "drive shaft" transefers to the lead screw inside the track. This let the gear come out and not transefer the power. The problem I encountered was that the thread size and pitch is EXTREAMLY rare. It's M16x1.00 . No one makes this size die or bolt or anything else (at least that I could find). So I went up and got a M16 oil drain pulg from a local place and "made it fit". You need to drill it out also.