Alright, here's what I did. I got rid of majority of the water with a shop vac, then looked around the hood there was a lot of water in a panel around the battery. Removed the battery and there is a drain right underneath, which was completely clogged with old leaves and garbage. I don't hear any water splashes and it is suppose to rain some more tonight so lets see what happens. I still don't understand why just the rear driver side? Could it be because there is some connection between the drain and the air vent on the driver's rear side?