I have used talcum powder to stop the squeeking. It seems to come from the bottom of the side bolsters squeking against the plastic base of the chair. Throw some talc in there and see what happens. If you can stand the way it looks its a cheap and temporary fix.

Darren '98 Mystique LS -Duratec, MTX Nakamichi CD-40z, Knauberized, KKM tru rev intake, 9MM Motorsport Wires, SVT Springs/Struts