Pop the trunk of your just-purchased musclecar and oh no! The trunk's floor is rusted, there's a musty smell, and the water collecting on the bottom of the trunk lid is dripping down. What happened? Well, before you start worrying that your latest and coolest ride is turning back to earth, take heed, because many Chevelles have suffered this fate.
As designed, the rear window of a typical '64-72 Chevelle features a hidden trough just below the rear window's lower stainless molding, which does not drain. When water runs onto the car, it naturally collects under this molding and remains there until it evaporates. This can take days-even weeks-to dry out, and each time the car gets wet the water travels into the trough again. Over time, this sitting water rusts the metal until the water has a passageway to leak into the trunk. On convertible models, the water's path to the trunk may open up even sooner, because the water typically has a less complicated path to negotiate.
Once water arrives unnoticed in the trunk, the large vinyl factory mat traps the water between it and the top of the trunk's floor. After several years of moisture accumulation, the trunk floor is next in line to rust away, just as the lower rear-window sash did a few years earlier. Whether your car is from the Snow Belt or the deserts of the Southwest, chances are water has attacked the trunk floor of your Chevelle, leaving rusted-through metal. In many cases, you even see the top of the fuel tank and/or the bracing below the trunk panel.
As relentless and extensive as this damage is, it's good to know that the repair is straightforward. With a day or two of work, new trunk floor panels, and some common body-shop equipment, you can make your trunk's floor new again. Of course, while you're tackling this project you should also take a look at your back widow sash's condition and repair that as needed.
But for this story we're sticking to the ins and outs of trunk floor replacement. Our candidate for this is a '64 Malibu SS convertible that, although a Southern California car since new, has suffered the same rust problems that many other Chevelles have everywhere. With our new trunk floors from Goodmark Industries and a few tools, we'll have this Chevelle's trunk looking better than new.
 |  The floor of this '64 A-body...  The floor of this '64 A-body had water trapped below the trunk's vinyl mat for years. The bottom of the trunk was rusted so badly that the top of the fuel tank was exposed. This is not only ugly but also unsafe, because engine exhaust can travel through these openings and into the passenger compartment. |  Before doing any repairs to...  Before doing any repairs to the trunk floor, we first removed the fuel tank. To do this, disconnect the battery, remove the wires from the sending unit, and drain, loosen, then remove the tank. A big piece of plywood located next to the car is a good place to set the tank immediately after removing it. |