So... I got a '99 Seville rear antisway bar to install on my Riv (it's the same as the STS bar). My old bar broke (it outlived 3 pairs of links, I installed Moog Problem Solvers and.. oopsie... good bye bar end). The new bar looks about 1-2mm thicker than the old. For you GM gearheads, the old bar is "green" and the new is "yellow."
I wrapped the working segments of the bar (where the bushings ride) in teflon tape coated with a paste I made of tune-up grease (polysiloxane) and graphite, and over-wrapped the ends with amalgamating tape. I assume the teflon will wear through in a while. We'll see how the rest of it lasts.