I've come to realize this week that somewhere in my truck, I think its my driverside back door, I have a large amount of water. When I start and stop I can here it sloshing around. It sounds like a significant amount. I remember seeing a thread on something like this awhile back, but am unable to find it. It could also be in my driverside rear quarter panel. What's the best way to get it out once I figure out, where it actually is?