as for the 02, I gots one myself, and while I love Jason and all he does for us here, the four-pod housing (this being the one that pops into the area where the OnStar push button swith is found in vehicles so equipped) is an easy order item from your GM parts supplier of choice (I got mine from GMPD). You will need the four pod housing (that alone tells me you do not have OnStar), some "aux lamp" switches (they are left side only, meaning you stack them on the left) and a pack of covers for the unused pods. All of these part #s are listed in one of the master GM part # lists that are maintined on this forum, a helpful moderator will no doubt be along shortly to link it you

And then you need the holy grail of this sort of operation - the correct wire plug for the aux lamp switches, so you can actually wire them up. That one I cannot help you with, Jason may be able to save you there.
I have no clue if the 03 have the same cubby or OnStar pod available for this sort of thing.