Let me know if/when you figure it out. I have a similar issue. Lubed up the sway bar bushing, but still a squeak over bumps or when I initiate a bump by pushing down on the trunk.

1999 Contour SVT #1966/2760, Silver Frost/Midnight Blue Koni Kit, Mille Miglia MM-S rims, B&M shifter, Stazi mesh, SFCs, optimized Y-pipe & TB, SS break lines, K&N drop-in, Infinity Kappa speakers, MTX amp/sub