Yes, I have created a system that plugs into your center console 10 pin CD changer harness with NO cutting of wires! You do need to find an ignition on source, battery always on source and a ground for the Sony cut off transmitter that goes between the factory stereo and the CD changer. Actually, Ernesto worked with me quite a bit on this project and I bought the Sony cut off from him. What I did was order a GM 10 ft cord, with a 10 pin male plug on one end, went out to a local store and bought a STOCK GM Female universal 10 pin with wires already inserted, I then popped out all of the wires from the stock female 10 pin plug and put them in the proper order to match the factory wiring harness. I then put the sony (it has a set of RCA inputs) in between the factory 10 ft harness and the stock modified female 10 pin harness. Basically all of the wires are still connected to the CD changer with the exception of the L, R and Ground wires. THOSE are run through the Sony RCA cut off module, SO, when you turn on your IPOD, XM Radio, Zune, etc, the Sony module picks up the slight milliamp signal from your aux source and cuts OFF your CD changer. The head unit still shows as if a CD is playing, but your alternate source takes over with CRYSTAL CLEAR DIGITAL sound! When you turn off your Aux source, 10 seconds later, the CD changer kicks back in.
Now I bought the long cord because I am moving my CD changer into the trunk and bought a factory insert for the center console, you would NOT believe how much space you have in there when you remove the cd Changer. I have this setup in my car now and it is working very well.
I still need to move my CD changer into the trunk and I purchased a hard wired adapter for my xm Color Express radio, which also has not been installed. It has been very cold here in NJ and the first weekend that it is 40 degrees or warmer, I plan to finish the install and leave feedback on the whole system. Just want to make sure everything works properly before I recommend the system to everyone. I have a few pics of what I built and I will try to get them up this weekend (feb 2).
Had to put new brakes on the car last weekend, else I would have finished the stereo project. But, then again, stopping the car is a bit of a priority over listening to a stereo!

I put on Raybestos Rotors from Rock Auto (they have a coating on the fins and the metal part that touches the rim, which prevents rusting) and Monroe brakes (they are one of the few that have a wear sensor built into them) VERY happy with the after market rotors and brakes, Rotors are advertised to stop the car 20 feet shorter, 30% increased brake life and Mill Balanced to be perfectly straight with no shimmy.