What were they thinking?

A Pontiac GranPrix rolled into the shop one day,dragging it's tail. It had come from the factory with a self-adjusting rear air-suspension system. Well it had quit self adjusting,and IIRC, the owner had just jacked it up and jammed some wooden blocks in there.. A new system installed IIRC would have been $4000C , and the car wasn't worth half that. I'm not sure what I did, that was a long time ago. I seem to remember installing some regular coilspring struts in there that the service guys found.IDK, I don't try to remember non-Mopar stuff.