Here are my experiences about wandering and "loose" feeling in e.g. driving over a bump:
- first thought was steering itself; either idler or tie rod ends: no play, not changed
- then tried changing both wisbones and drop links, as well as shocks (this was cause one shock was slightly leaking)
- had wheels aligned, but they set the camber too close to minimum
Still had these strange feelings and thoughts about all not being right. Then the cambers were re-set to exactly to the factory setting and wowsa, now it rides as it should!
As a conclusion from the above it seems, that Omega is extremely sensitive to camber. Also the structure of wishbones is not that convincing for a heavy car like Omega. All suspension parts are quite easy to change, so my recommendation is to regularly change the wishbones and droplinks every 100k kilometres and have alignment done every time something is changed in front; even tyre change seems to alter tracking (found this out between the two latest alignments)
Still may have too much camber in rear wheels. When fully loaded, the tyres seem to run on inner shoulders and might wear, but not that much. Have to try new rear springs to avoid that.