Quote Originally Posted by Max@034 View Post
Classic symptom is when you pull into a driveway or parking lot (so the wheels are turned), and at low speed you hear and feel a clunk. Otherwise, just a general mushy feeling in the steering can be an upper control arm. Replace them in pairs (2 on each side at a time), otherwise you will just accelerate the wear of the already used one and find yourself pulling the strut once again.

You should also take a look at your upper shock mounts. They are often overlooked. But since the problem started after you installed coilovers, I am going to lean towards you forgetting to tighten something up.

Were the coilovers brand new? Or used?
Good description for the front, but OP was asking on the rear.