JB Weld & Beercans- The Body Man's Choice

It was apparently a design feature for GM cars to rust out around the rear window, which let water get into the trunk to rust out the quarter-panels and trunk floor.  Even though it's spent 33 of its 34 years in relatively dry California, my Impala is no exception.  The solution?  Buy some JB Weld, cut up a beer can, duct-tape the beer can metal over the rusty area, then apply several liberal layers of JB Weld.  Works perfectly!  This repair was done three years ago and is still leak-free and looking good.