Note - this applies to a 2005 AV...
I installed a Valentine One and hardwired it in. Jason P. gave me some advice, as he did it on his truck as well...
Remove the overhead console. There is one screw toward the front, and two clips toward the back. Once you take the screw out, just gently pull down, with a bit of rocking motion, and the console will come down. Diconnect the wires for the map lights, and you can get the whole console out of the way.
Work from the passenger side -- this is a tight area to be working in. Get a small (2 AA) flashlight, and insert it in the headliner area above the passenger side, pointing at the driver side.
Locate the bundle of wires that are glued down above the driver side. Carefully cut away the outer black tape to expose the wires. You are looking for the red wire. (This bundle is the wire set coming from the mirror. By tapping into power here, the detector will come on when you start the truck, and shut off when you shut the engine off. If you were to tap into the overhead lights, the detector would stay on for 20 minutes after you shut off the truck, just like your overhead lights will if you leave them on...)
Tap into the red wire for power. The V1 came with a nice little tap for just that purpose, and was prewired with an in-line fuse (recommended!). You will also need a ground -- I just drilled a small hole in one of the metal flanges above the conole area, and set the ground with a sheet metal screw.
Now just feed the connector to your detector between the headliner and the windshield. I positioned mine up high in the tint band -- it is almost impossible to see form the outside. Test your connection. Replace your console (don't forget to reconnect your overhead lights), and you have a very nice, almost invisible detector install!
Hope this helps.
(If you are in the market for a detector, the V1 is a very high quality unit - goto
http://www.valentineone.com for information. Pricey, but I think it is the best on the market.)