hardwiring cell phone dock

Hey guys, I have a 2007 Prius. I just got a car dock for my nexus one phone, it comes with an adapter that plugs into one of the 12v utility sockets and supplies the phone with 5V (max 2A).

I also use this phone for music, plugging it into the aux jack in the center console. The problem with this is that the aux jack and the 12 socket use the same ground, so there is a lot of noise in the audio.

What's the best way for me to work around this? Either taking apart the 12v adapter and wiring it to some other 12v source, or if there is a 5v line somewhere inside the dash I would be ok with cutting the adapter off completely and just wiring straight into that.

Also, could someone link me to a thread of a mod that involves removing the dash on the drivers side? I had to take various pieces off before to install an EV button and a 'radio unlock' switch but parts around the steering wheel seems harder to remove (Trying to run the audio cable)

Thanks for any help.

 

the audio is good when the phone is not in the dock, as soon as I pop it in, the noise starts.

I'm actually plugging it in under the dash rather than in the console.

The noise is not coming from the charger itself, it's coming through the speakers, I can control it with the volume knob...

I mentioned it being a ground issue as that's what I was told on a forum for the phone model(others having same problem with different cars), and it made sense.

 

The dock provides power, a mic, and a speaker. I have the mic/speaker disabled and am plugging the 3.5mm jack directly into the phone (just as if the phone were out of the dock. If I pull the power adapter out while the phone is in the dock, the noise will go away.

The noise exists with either utility socket (under dash or in console)

It is affected by things like electric motor activity and turning my headlights on(the latter to a lesser extent)

I'm also thinking about getting this LiquidAUX™ Bluetooth® Car Kit - K33428US - Kensington, so I would only need to run one cable to the phone (A usb cable to the bluetooth adapter for power). I think it might have the same problem though, though the problem now with the bluetooth adapter and not directly with the phone? Just thought I'd through that in there.