Last night I swapped the stock shocks (FE3 suspension) back in and the difference was night and day. When I looked up the shocks that had been in there that came with the Gold-Line springs, I discovered that they were designed for lowered full-size trucks (DJM-1409, IIRC) and I've seen a lot of complaints about how rough the ride is with them. If it was bad in a full-size truck, no wonder it sucked in the HHR. I must not have noticed how bad it was at first.

I'm sure it's covered elsewhere, but does anyone know offhand if the ACDelco 560-607 rear shocks for the Cobalt FE5 are shorter than the ACDelco 560-547 for the HHR FE3? I can't find specs anywhere online.