Brake Light On problems of the 2000 Mercedes Benz S500

Last night we had tropical storm eta in florida. We had about 10 inches of rain. The temperature was between 70f and 80f. The car was parked on high ground but in the rain. The inside of the car flooded with water under the carpet. I have not determined the source of the leak or the source of the short yet but the car is in my shop. I drilled holes in the floor to drain the water for now. The entire electrical system went crazy. The abs was malfunctioning, the wipers were turning on and off, the brake lights and other lights were turning on and off on there own, the car stayed running with the key out of the ignition, the lights would turn on and off with the key out of ignition, the sos light was turning on and off, the airbag light was turning on and off, the speakers were popping, the throttle controls were acting odd and not corresponding with the throttle control, they would not respond or stay on longer than normal, the transmission was getting stuck in gears, the air suspension was acting weird, I pressed the trunk release and the tail lights started flashing, the gas gauge read empty and I had a full tank, the speed and rpm were working normal, outside temp was going on and off as well as the clock, the ac blower speed was changing and turning off, the windows would work then not work, the interior lights were turning on and off, basically the car would start and run but almost every system in the vehicle was malfunctioning. This is the second mercedes I have owned that did this. I took videos but they were too big to share.