Originally Posted by timmyr

" It seems most noticable when moving slow and hitting slight or shallow dips in road"

A few years back, when my W124 made a loud squeaking/creaking noise over speed bumps and shallow dips in the road, the problem turned out to be the ball joints.

So before you go drilling anything, it couldnt hurt to try and squirt some oil inside the ball joint protective boot to see if that resolves the problem.