heres my Ls with stock springs and 17's with 215/45/17 tires. your gs wouldnt be much different than this. i put eibachs in to lower it and they made things much better. i then bought a full air-ride system and finished the installation today, so now im looking to sell my eibachs lol.

and here it is with 17's and eibachs and svt skirts...
