I wired a spec.dock for my iPhone to my 09 tt and I'm getting fm interference when the iPhone is docked. The dock is connected to the factory aux in so it must be the power ground. Power is attached to a fuse tap so it's got it's own fuse and ground is attached to a bolt near the fuse box. Spec dock vendor says to move the ground to the back of the radio. Putting the phone in airplane mode makes no difference, it's the power-ground charging the iPhone I'm sure. Getting the ground up to the radio may be tricky so I thought I'd ask here. Do you think that will help?

Steve