Well my 370Z has the Eibach Pro Kit Performance Springs with from what they say it lowers the car .9" in the front and .8" in the rear the stance is beautiful and it handles better but i don't know if it's becouse of the springs are upgraded sway bar or gt ladder brace (they were all installed at the same time) but over all for me it's not worth it. The roads here suck i mean i go very slow at an angle in and out of driveways speed bumps and what not but is scraps the S&*% out of most stuff, just the plastics mostly but ya know i still sucks. It's not like this is my 1st low car had a vette that was darn low but here's some pics..
the black plastic under guard is only 2 and 1 quarter inch from the ground it's the lowest spot and what rubs and the front under gurad is 4"
just my thoughts..