I recently put a Jensen VM9725 with Nav head unit in my 2004 with Boise 10 speaker set-up. It was quite a pain in the butt! Im not happy with the Jensen at all. The sound quality is poor and the Nav system keeps cutting out or low memory issues. I did run the USB cable from the rear of the unit down to the center console so i can plug my ipod into it without messing with the front USB, it works pretty slick. I like the blue-tooth also (didnt have it before) but the Jensen is low quality for the money. Im probably going to replace it with the Kenwood but im dreading taking the whole console apart for the hundreth time.
The steering wheel interface is plug and play, only problem is finding the space to stick the unit. It s not big but space is limited in the dash. I also have the Boise interface which is hugh plus all the RCA cables makes it pretty crowded back there.
Good Luck