Originally Posted by Volk Z

Are they set to the same height on both sides? The pics look like they differ. I was attempting to adjust the drivers side lower to match the rear ride height when I discovered the issue. As you can see the adjustment is quite different and I would still need to go lower on the drivers side to get it down another 1/4"I can tell you from doing around 10 sets of coilovers on the Z the front right (battery side) and Rear left are the "lower/heavier" corners. They are approximately 1/8 to 1/4 inch difference.

THe difference you have is not right in anyway.

Here are my questions.
1. Is the preload set to the exact same amount? (should be set at around 1/4 to 3/8 inch).
Preloaded at the same amount or with the shocks completely removed the result is the same

2. Are these used? Are the struts in perfect working order and are not blown?
Coilovers are brand new and both rear shocks are in working order and adjusted to the same length, not sure if this is relevant but they are adjusted as short as possible and provide 5/16" of preload on both sides when the spring perches are adjusted to the passenger side length in the picture above

3. Are the spring the same length? Manufacturer may have varied spring heights and maybe messed up here.
Springs are the same length and were swapped side to side incase one was mislabeled to a higher/lower spring rate

4. Do you have any excess weight on the rear of the car. I.e. subs etc.
I have found that every 50 pounds or so lowers the rear approximately an 1/8-1/4 of an inch depending on the spring rate type (8k is typical for rear).
I do have a sub in the trunk which sits dead center, removing it is easy enough but I can't see that being the cause