Here's a quick How-To for installing the Progress Technology Rear Anti-Sway Bar on your HHR. A simple install, it requires about 20-minutes and a 15mm wrench. Sway bars are best installed with the vehicle on the ground to prevent improper preloading of the bar. For our How-To, the pics were taken on an alignment rack - leaving both wheels on the "ground" and the suspension loaded as it would be normally.