Areas that rust - Snorkel box

This is behind the tail-lights..

Notice the water that drips in through the air-intake vent grill above, and can end up damaging electrical units (on injected petrols), rusting the seam above the chassis, dripping down into the chassis and rusting that badly as well (the bottom filler plate)

One solution is to at least drill a hole in the centre of the floor where the pressed fingers cross... so water can drain down and out