Santa is bringing me a new stereo for Christmas, as I'm tired of not having bluetooth and iPod integration in my car. I've got a 2004 Grand Prix GT2 with the Monsoon system, steering wheel controls, but no On-Star. I've also got a HUD, but I don't think there's any hope of me retaining the radio functionality of that...I'll live, just as long as it still works for the other stuff (speed, compass, temp, etc.). Here's what I'll be installing next week:

Clarion CX609 head unit - Amazon.com: Clarion CX609 2-DIN CD/MP3/WMA/AAC Receiver with USB Port: Electronics
PAC SWI-JACK (cuz I'd miss the steering wheel controls!) - PAC - SWIJACK Steering Wheel Control Interface - Blue - SWIJACK
Metra GMOS-04 - Metra - Replacement Interface for Most GM Vehicles - GMOS-04
Metra double-din install kit - Metra - Installation Kit for 2004 - 2008 Pontiac Grand Prix Vehicles - Black - 95-3527

So...before I embark on this project, any warnings or tips? I haven't done an install in ten years or so, but I think most everything is pretty straightforward. The SWI-JACK instructions leave much to be desired - I'll probably have to do some more research on where those wires need to get spliced in. How is the install of the GMOS-04? Any splicing to do (aside from connecting to the HU harness, of coures)?

I'll try to snap some pics and post them here. Looking forward to finally upgrading!