I have a coolant leak that seems to be coming from somewhere behind my passenger side front tire, so I'm thinking it may be from the overfill tank. Does anyone else have this problem or know how to deal with it? Thanks.

 

That is also the area where your water pump is. Hope its not that cause its expensive. Mostly labor.

 

Check the hoses - there are a lot of hoses on that side - from the radaitor to the thermostat, from the the top of the radiator to the cololant overflow, from the bottom of the overflow back to the radiator etc. etc. you get the idea...