You may have noticed that most 1990-1993 Honda Accords have significant rust in the rear fenders above the rear tires while the rest of the body is rust free. There are a few causes.
The first cause is road salt and grime being kicked up in between the rubber splash guard and the lip of the fender. Car washes do not get to this salt and grime, and so it begins corroding the fender on the inside. By the time you see the corrosion, the fender has started to significantly rot.
The second cause is the drain hoses from the roof that are behind the upholstery panel in the trunk being clogged and allowing water to collect behind the fender.
If you have immaculate fenders, prevent this problem from occurring by REMOVING the rubber in the rear wheel wells so that there is nowhere for salt and grime to accumulate in a “hidden” place. Also, make sure the drain hoses flow freely.
The root cause is the fact that Honda (cheaply) failed to paint both sides and the underneath of the render, even though it was obvious from the design that the fender would corrode from both sides and underneath. There is nothing that can be done about it now besides to prevent the corrosion from starting. Once it has started, it is extremely difficult to repair. Once a rust hole begins at the fender, water will then leak into the trunk and corrode the inside even more!
Cooling fan runs after motor is shut off
This is perfectly normal. Spooked me though!