The front suspension is fully adjustable, about the only 'upgrade' item would be the spring rate on the QA1 shock. A few builders have put a front swaybar on with mixed results. The rear suspension is somewhat limited to coil over struts, spring rate, suspension bushings and a swaybar. Unless you plan to add a front swaybar, the aftermarket Cobalt swaybars are far too stiff, as Gtstorey mentioned. The rear strut geometry is pretty much fixed, unless you want to modify things. A couple builders have gone down their own path with the rear suspension and put double a-arms on with extensive modifications.