when i turn my stereo on, there is a popping sound coming from my rear speakers. (it sounds like its only the passenger side) its only on power up, but its every time the unit is turned on. could this be a faulty ground? i've got it grounded to the only place that the wire would reach...there's a bracket running behind the center console on 5th gen's with two sheet metal screws in it. the system seems to function normally, which would not be the case if the ground was bad, right? any suggestions? other than this, which is installation error, i'm sure...the stereo is great (alpine 7863). i'm just using the stock '01 gxe speakers for the time being but the new head unit makes them sound pretty descent.