Rocker Panel Replacement

At first glance, the rocker panel looks pretty solid aside from a few small holes near the back.

Oddly enough, BMW chose to sandwich the rear quarter panel over the rear portion of the rocker structure, inviting rust to form between the two layers of steel. This became apparent when we cut away the outer quarter skin.

To remove the rocker panel, we took an angle grinder to the spot welds. A grinder is quicker than a spot weld drill bit. It's also very effective if you're removing a panel that you don't plan to reuse.

With the rocker panel off, you can see the horrors that lurked beneath—well, not horrors, just lots of surface rust that, if left unchecked, will become much worse.

After removing the surface rust with a wire brush wheel, we applied OSPHO rust treatment to the solid metal.

We then used Eastwood's Rust Encapsulator paint to treat the inner rocker structure.

The Eastwood paint should prevent any future corrosion in this hard-to-reach section of the car.

We sourced our new BMW rocker panel from Bavarian Autosport, and it fit perfectly. We used Vise-Grips to secure the panel to the car while we welded it back on.

We purchased a small repair panel from the German firm Walloth and Nesch. This piece saved us a substantial amount of cash by allowing us to reuse the rest of the quarter panel.

Here's the nearly complete repair. Notice that we're butt-welding the wheel opening, as we cut for wheel and tire clearance in anticipation of some 2002 Turbo flares.