I don't know if anyone mentioned it yet, but re-check torque on the rear toe link bracket. I know you torqued it...just check it again. I had that problem once.
I also had an issue with the ball joints wearing out on the rear. They were brand new, from china, and were shot in about 2 hours of driving. Jack up the rear, yank on those rear tires, and make sure they don't wiggle.
Finally, what does your ride height look like front vs rear? mine is a bit high in the rear, and it can feel unstable during heavy braking. I think the weight transfer to the front, combined with the already high rear stance, can make the car feel darty. I was going to lower mine in the rear just a bit, but haven't gotten around to it yet.