Thanks to Buford
Look at the thin wedge of front fender just in front of the front door, the part where the V8 badge is on 97-99 SHOs. Now with the door open follow the fender down to where it connects to the rocker panel. This little pocket can hold most road dirt. which will in time cause rust through.
With the door open you can get a hose positioned about where the V8 badge is and shoot down cleaning out the pocket with out spraying any dirt or water into your car.
Give it a shot, get rust before it gets your SHO.