Read this:
https://nasaspeed.news/tech/suspensi...cts-and-cures/
In summary, you should replace your shitty factory rubber bearings with metal spherical ones
Solution here:
Throw away your SPC crap
Visit SPL Parts (
Nissan - 09+ 370Z (Z34) - SPLParts)
Get:
1) Rear Traction Arms (because PBM coilovers are true-type)
2) Rear Toe Arms
3) Eccentric lock out kit
4) Rear camber arm
5) Front upper control arms (might as well, while you're at it)
Take parts and car to your local performance suspension/alignment. Install parts. Get new alignment. Dial down the camber in back to the minimum needed for wheel clearance
Profit
(As an aside, if the car is high mileage, you should inspect the bushings in the rear suspension to see if anything is worn out, and replace anything you see thats f'd up)