Done and done! It was really a pretty painless project. The CX609 is a great radio for the price (<$250), considering it has USB/iPod + Bluetooth built in. Crutchfield says it doesn't fit in a Grand Prix - believe me, it does. There are some annoyances with the iPhone when you use both Bluetooth and USB, though - if the BT pairs up after it's plugged in, the source switches to BT audio and requires some manual intervention on the phone to get it back to USB. I'm still trying to figure out how to work around that, as I'd prefer not to use BT for audio.
The GMOS-04, despite all the horror stories I've read, has been working well the past week. There's a nice grounding screw near the back of the radio, so I tied all the ground wires together to give it a little extra ground. There's still a tiny bit of static and engine noise - not enough to bother me, but I might try some of the tricks I've read here to solve that one.
The SWI-JACK works well (though I do miss my 1-6 preset cycle button - will have to get used to the up/down cycling presets). My tip for installing that is to find another harness with the same pins as the GMOS-04 (I was fortunate to have one laying around) so you can add pins 6 and 7 to the harness - saves you from having to do any splicing and gives you a nice clean install.
