, I will pay closer attention the next time we speak. My wife says the echo occurs when she calls me in the car. I've tried turning down the volume on my cell phone, but don't know if that helps with the echo problem or not. My phone is a Galaxy Note 4, but I've only had it a month. The crackling is consistent between my previous phone (Galaxy S4) and now my Note 4. My car is VIN 2204.
P.S. Your Inferno idea is nice, but unfortunately my car blows that theory out of the water.