None of the mounts are originally solid on any of the years. W bodies can buy one that is called solid, but they are simply unfilled. Typically most mounts are filled with oil.
the hockey puck or that white mount are going to be your best bets. The mount Dan speaks of is totally different in his year than yours. You need to remove your mount and change it out.
As for the rear and side mounts in your year. They can go bad, but typically the front is the first to go and once that is taken care of, the other don't usually have problems.
00 Regal GS: All kinds of cool stuff.