This is my friend's GSR after we just lowered it on Ground Controls and Tokico HPs. In the pic it's lowered 3 inches but we had to raise the front up a little because he couldn't fully turn his wheels. Even after he got it corrected with a Skunk2 camber kit (he was cambering at -3.1) the guy got it to -1.2 I think but he couldn't fully fix the camber because his wheels would rub. The guy was like "this is the best camber kit I've ever seen!" haha
Lesson learned: It looked so good we almost splooged our pants but...you can't lower that much and expect no problems.