I went outside and found my baby girl was leaking. The leak is at the rear driver side wheel area and looks to be coming from the gas tank. I think it's the filler neck but I want to confirm this with you guys. I attached a photo. What do you guys think this is, and if you know, what's a general cost estimate for repair? Muchos gracias.

 

Not a great picture, what kind of fluid is leaking?