E9 Coupe Rust Diagrams


Rocker Panels:

The "rocker panels" are located below the doors and extend from one wheel well to the other. Even though rocker panels on most cars are important, the fact that the CS doesn't have a "B" pillar makes them that much more vital. A decorative rocker cover is mounted on the outside of the rockers, which can hide just about all of the pesky rust underneath. The cover must be removed to inspect the panels properly. Pay extra attention to the areas at the front and rear.

Rockers can rust from moisture collected from the road wheels and exposed areas from rock chips, and also from water that enters from the sunroof drains. On cars with sunroofs, BMW decided to run the drains down through the "C" pillars, in front of the rear wheel well and out through the rear of the rockers. If the drain holes formed in the rear of the rockers clog, moisture sits inside and contributes to rust.