2theedge1974,
I traded a 2002 access cab for my 2004 double cab. My 02 had the 6 disk, the 04 does not. I tried a 6 disk from another tundra and it didn't work. I later found out that there are 2 systems, an analog one and a digital one. In my case and yours we were trying to put an analog head unit in a digital system. (The amp in the digital system controls volume, etc based on digital signals from the head unit.).
I started off looking at some way to get a changer in the truck, then a Kenwood Music Keg, then saw the Camry/Solara NAV unit (see
www.oemvalue.com), then got excited about and decided on the Kenwood 7015 double DIN in dash DVD player with 6.5" touch screen, Sirius controls, Nav controls, and more. It is awesome. I installed it myself but a local stereo shop can install it (or anything else) for you. The only problem with the double DIN units is that the space in the dash is a little wider than double DIN, leaving you with a little bit of space. A custom dash kit needs to be made if you don’t like the space, no big deal, a little piece of painted wood or Formica.
A third option is a single DIN unit using an install kit that has the little pocket under it. You can pick any head unit you like with this option but if you won't like the look of the pocket or aftermarket unit GO with the Kenwood or oemvalue option, you will be much happier in the end.
I LOVE my Kenwood, I just installed the Sirius controller tonight. I will call tomorrow and activate the service, I am excited about that. : )
As far as the steering wheel controls PAC makes an interface that will interpret your button pushes and using an IR transmitter send commands to your new unit. You train the PAC using your new head unit's remote control. I wrote a big article on this, I can find the thread and give you the link if you like. Let me know.
BY THE WAY, Crutchfield, I learned, doesn't know/think that ANYTHING will fit the tundra. They told me the PAC unit would NOT fit the tundra but it does and the instructions even have it listed. If you have any questions let me know, I am actively installing all sorts of stuff : )
-zboyblue