Alright, do I've got Koni yellows with a ground control coilover setup. I have a knocking in my rear passenger strut and I can't figure out where it's coming from.

I've replaced and triple checked the bushings (OEM solid mounts).
I've replaced the springs with different (softer rates) to see if it was just excessive spring rate.
Everything is torqued to spec. Bottom bolt, three top plate bolts, top nut.

The sounds is present over small dips in the road. Big long bumps don't make any sound. It sounds as if the wheel is bouncing on the road.

Would that be a symptom of a blown damper? I'm running out of things to check.

Did you figure it out yet?

My first thought is an incorrect sized bolt. As in the bolt is smaller than the hole and as the suspension cycles it knocks on the bolt.

I have the same setup. The spring is too short with the OEM mount unless your perch is screwed all the way to the top of the sleeve. You lose at least an inch of height from where the spring sat on the stock mount. Get a set of these Genesis spring spacers to put on top the springs and you'll be set.

http://www.amazon.com/Genesis-2-5-Spring-Spacer/dp/B000W7F2EA

my springs are slightly compressed at full droop, and I do have the spring spacers. I have a new shock absorber on the way from Koni.

ahh well then hope that fixes it. Did it sound like it's coming from in the trunk or outside/under the car?

If you take it off the car blown damper should extend back out fast after being compressed and feel more like a spring than a damper. Any movement should have resistance in a good damper, and it will move out slowly after being compressed.