I took it in today to have the water sound and a front suspension sound checked out by the dealer. They were able to verify both sounds. For the water sound, it was a clogged air conditioner evaporator drain that they flushed out.
The front suspension sound was the TSB 13-09-03 for some kind of bushing. They had to order the parts for that, but will do that under warranty, as well.
2013 Mustang GT Premium (6 speed manual, 3.73 gears, GT500 axle-backs, no resonators), 1998 Pontiac Firebird Convertible, 2003 Jeep Grand Cherokee, 2007 Honda ST1300, 2001 Ninja 250