Has anyone experienced this?
Situation: I connect my laptop via a 300 watt inverter to the rear power outlet. I want to watch a dvd, when i connect the Aux audio cable from Headphone jack to radio aux input i get a HIGH squealing noise. Do i need a better quality inverter? or what?.... when i disconnect the laptop from the power ... no noise.

 

I wouldn't be surprised if this has to do with the ground on the HHR, which by the way sux! I have my Sirius getting power from that outlet. at first, when it wasn't powered, I would get engine whine through the radio. I haven't heard it lately. I hope GM does a better job in grounding this vehicle on the newer models...

Ng

 

My cell phone adapter whines in the front socket but not the rear one. Might have to clean up the ground points around the vehicle one of these days and see if that fixes the problem.