[Grant Garrison]

Bob-- This is somewhat of an uneducated response, but one quick, easy way to find where it's coming from is to spray some silicone lube on 1 bushing (or pair) at a time. If said squeaks disappear, you've sourced the problem.

Given it sounds like it's coming from both sides, and is more of a low speed issue, I would tend to look at the shocks. I have heard that Superformance replaced the Spax shocks due to long-term reliability issues. Perhaps yours have reached their half-life. Is there any oily residue around the shock's housing? This would be a sure sign that the seals are going.

Other possibilities would be the halfshaft CV joints, but I'm getting way beyond my mechanical know-how. Perhaps your Superformance dealer can offer a few suggestions. Good luck.