Ok so I've been looking around here quite a bit and I've come to the conclusion that these are the things I need to buy.

Headunit - Pioneer DEH-P4000UB CD receiver at Crutchfield.com

I don't know what this is called but I'm pretty sure I need it - PAC C2R-GM32R (pac-c2rgm32r) Pontiac Wiring Harnesses In-Dash Receiver Accessories & Installation Car Accessories and Installation Car Audio and Video - Sonic Electronix

I also am looking for something that will make the spot for my headunit fit a single din. ('03 Bonneville SE'* are double din right?)

If that list is correct and includes everything that I might need to buy to install an aftermarket headunit please let me know.

looks like everything to me. but do me a favor. before you buy from crutchfield. check onlinecarstereo.com and woofersetc.com and sounddomain.com to see if you can get a better price on all of your equipment

Alright, and do you know of anything that could make the double din (i think its double din) hole where the factory headunit is a single din. Something like a little storage cubby that'* 1 din.

Actually, I found this http://cgi.ebay.com/2002-2003-Pontia...3286.m20.l1116

Lol, I'm kind of nervous ordering all of this stuff because this is the first time I've ever dealt with car audio. So can someone verify that this list of stuff will make it so I can use an aftermarket headunit (I'm using the factory speakers)

List:
http://cgi.ebay.com/ws/eBayISAPI.dll...tab%3DWatching
Harness
Dash Kit

1.) Will the headunit work in my car?
2.) Will the harness (I think it'* called that) work for my car?
3.) Is that the dash kit I need to be able to use a single din headunit?

gmos-05 is the metra harness part number 99-2001 is a dash kit on metras website that looks like it will cover up the blank but the one that i used that has the pocket is 99-3301.
here is the link Metra Electronics

the answers are yes, yes, and yes lol

the wiring on that is fairly simple and the only thing with the dash kit is it doesn't fit into the snap in connectors of the factory radio so you can drill 2 holes and add some screws to hold it in

I put a block of wood on each side and ran wood screws into them. makes a "sandwich" type of action that holds the kit in place

never thgouht of the wood blocks, I just went with what was fastest to do at the time adn it'* really easy to take out and put back in if you need to get to something

Thanks for all the help. Especially about the dash kit :p

So it is TRUE. 2K Bonnie owners DO need this PAC harness. Hmmm, wander what would happen if I bypass this...

you'd lose your door chime, and risk causing problems to the air bag system that could lead to it malfunctioning if you ever get into an accident. Not worth it dude. I think its way more important for you to be safe than to save money. I had to take it on the chin and buy one as well.