Audio Systems: cd changer noise, grand am gt, music tape

Question
Hello! I am having a noise problem that I can't quite tackle.  Here are the details.  

'97 grand am gt w/ orig. delco am/fm/cass.
older jensen 10 disc changer w/ rf mod. and
new sony xplod cdx-565mxrf

For the past few years I have been running w/ my old jensen changer in the trunk of the car. This changer had one big cord with a funky plug on both ends. Then the cord hooked into the rf box mounted up above the steering column. Out of this box came all the wires. The constant was tied in with the stereo constant and the remote went to the power ant. slot. The ground went to a car body bolt.  

The background noise sounds like a fast-paced swishing sound.  It is loud enough to be heard over soft parts in songs.  It stays constant in speed and doesn't change in pitch like alt. noise.  It increases or decreases w/ the car volume.  Also, when you change volume w/ the changer on, you can here this sound with each volume click(just say the f and t sounds together and you will nail the sound).Turn the changer off and both sounds go away.  

I purchased the sony and hooked it up. I ran a constant from the battery and a remote line back.  I hooked the changer up to those and the ground runs about 2'to a bolt that holds the spare in place and goes right to the trunk floor.
Also the modulator is in the changer.

I am getting the exact same noise with this changer! The sound is coming up through the ant. line on both changers.  Unplug it and the noise goes away (along with the music). Tape play and am/fm work fine.  I even tried changing the stations that the changers use.  The noise is present with the motor on and off.  

I wrote to one of the other guys and they mentioned that the changer's laser could be causing the noise with the tuner.  Would it do that since the changer is in the trunk?  SHould I try an antenna filter or maybe junk the factory ground wire for the headunit and do my own ground for it? Thank you in advance for any help you might be able to give me.  

Answer
Run all the stereo components ground wires (except any big amps) to the back of the head unit ONLY, and ground together, with whatever wire grounds the headunit. Let me know what comes of this mod. Don't let the cases of any changer or other component be in contact with metal, use plastic grommets to mount them if you have to, or mount them in a wood panel and mount that to the car.