There are two drain holes Mark, one in front of the pollen filter and one under the wiper linkage, the later will be the pain in the butt to get too, might be easier to go from underneath via the engine bay. Incidental the rear quarters can let in water as well, but you'd see water in the boot. The AC is a de humidifier as well, get the heat blowing in the footwells with the AC on that should help it dry out quicker, its also a belter for de misting the windows.