I just installed the AVIC D3 in my 07 Ram hemi QC _myself_. It isnt that hard.
Call up sonicelectronix.com, and they will sell you the accessories you need. There is a Schroth harness that plugs into the factory harness and solders to the leads coming out of the D3.
They also hae a Schrothe mounting kit with a mounting ring that fills the extra space around the d3. If you dont have the factory navigation bezel, you can buy one on ebay. They have em in differnt colors with a sqaure cutout.
You also need a metra brand antenna adapter that lets you plug your factory antenna into the D3.
The only hard part of the install was that I fabricated two rack ears from aluminum to hold the D3 in place in the dash. I think crutchfiled has a metra install kit with metal brackets that screw onto the side of the d3, so you dont have to do this.
Good luck!
(Just call crutchfiled or sonicelectronix and they will hook you up.)