Remove the armrest. Single 14mm bolt.
Drill a hole, and add a gromet.
Remove the endcaps to the armrest, and run the wiring through the armrest. The grommet I had was too small for the connector. I had to cut the cable, run the wiring through the grommet, and then resolder it back together. (Forgot to take a picture, but you can see the existing wiring.
For a car adapter, I purchased a universal adapter from Radioshack. You can use it for different phones, pda's, mp3 players, etc. You only need to buy a different connector (~$2 per connector).
Next is to get power to the car adapter. I decided to get power from the backside of the cigarrette lighter. Probably committed a cardinal sin by cutting and soldering in the wiring. IMO, its much more reliable then a wire tap (provided you know how to solder). In case you can't tell, I added the white wires. Don't forget to pull the fuse, and measure the voltage before you do any cutting, or soldering.
Next step is to wire in a female portion of a car adapter (also from Radio Shack) to the cable just connected to the cigarrette lighter.
Connect the two, and their you have it. Power in the armrest. Still need to get a final picture of my phone in the armrest. Too bad with the Razr, it barely fits since the power comes off the side.