I have a 2007 cobalt ls. Recently lowered on sportlines. I now am getting horrible bounce from the rear that just started today and a bad clunking sound and a vibration that shakes the whole car. I can't pin point the vibe it feels like its coming from the rear but sometimes I can't tell. I noticed if I run 55-57 mph it will stay vibrating then smooth out and just do it every so often. It rode perfect all the way up till the past 24 hours and this has all started out of no where. Opinions?
Did you install brand new struts along with the springs? Did you put in Koni's or FE5's? We need to know cause the sportlines will blow out your OEM struts.
2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille