I have an 05 CC 4x4. I have a couple of mods but nothing serious. I do a fair amount of hauling and towing and I hate the sag I get in the rear when I do. I have been looking at a lot of the leaf spring helpers such as Hellwig and wanted to know if anyone had a set and what the results were. Is it better just to buck up and get the air system? I am trying to avoid that because I don't do enough towing/hauling to warrant the cost.