I'm getting a strange loud ticking sound, sort of like two metal plates colliding or banging each other. It happens when the car starts moving when I gently let out the clutch while in reverse, taking foot off the gas while in 2nd gear, and shifting from 2nd to 3rd gently with little of gas. What I hear is a single tick as if something was loose. It's pretty annoying and embarrassing, any ideas? Stock 2005 WRX, 30K miles.