It should be pretty straightforward, and I assume after installing a double DIN size GPS unit to replace the factory radio, just running a GPS antenna would be all that's required. The only issue with the Spyder is that the face of a GPS unit is below the line of sight, so you would get directions of the GPS called out to you, but the face of a GPS would be lower, so that you're taking your eyes off the road to look down at it- not a good idea.
I'd check Crutchfield.com to see if they have a GPS head unit that would work for you plus, you can see if there's any specific directions for the Spyder installation.
Some members here have GPS head units in their cars, so maybe they will respond shortly.