The first step is to buy your necessities:
1. a small can of Bondo Glass
2. a small can of Bondo Body Filler.
3. an iPad dock - I bought mine here: Fifield Fab Custom Car Audio - Products
- the iPad Mini M
4. Plasti-Dip (black) and painter's tape
5. LOTS of sandpaper in various grits
Once you've got all of that, the fun begins.
Remove the dashboard from the car and sell your Nav radio on eBay (you'll make around $700). Buy an iPad Mini with 3G with this.
Trim both the iPad dock and the dashboard so that they have a snug, semi-flush fit, with the iPad dock surface slightly more depressed than the dashboard. Melt the two pieces together to an extent. this will help strengthen your bond. I used a soldering iron.
Mix up some of the Bondo Glass, and spackle it onto the front and back. Try to be precise here, leaving minimal pockets of air. It'll look like a mess - this is OK.
Sand, sand, sand. Get it as smooth as you can once you've waited for it fro dry for a day or two. You'll reveal air pockets once it's all smooth - this is OK. Get your Bondo Body Filler and spackle that right over all of them. Again- wait a couple of days and then sand again.
It's a pretty repetitive process until everything is as smooth and shaped as you'd like it.
Once it's all good, it's time to spray. Tape off the rest of your dashboard except the middle panel and spray away. I gave it 7 coats of plasti dip and let it dry a few days. Don't spray where there's dust, and when you're ready to peel off the tape, run a sharp razor blade at the seems so that you don't pull of the rubberized spray paint with the tape.
That's it in a nutshell!