^JB is right, for the code just call AoA and they’ll help you out. If that doesn’t work, there’s a guy on eBay who can retrieve that code for you if you provide him an AUZ number from the nav unit. I think he charges 10-15 bux.
I’ve retrofitted successfully RNS-E myself. You need the following:
•RNS-E w/code
•RNS-E wiring loom/adaptor
•Diversity/Radio antennas adaptor
•GPS antenna
•misc basic tools to remove radio, drivers knee bolster, etc…
•an hour or two of your time
As far as main wiring loom, from what I’ve seen when you order one specific to your car specs(Bose vs nonbose, cd-changer, sat radio) vendors almost never get it right anyway. I have pin out diagram, so when you’ll receive yours, you could double check their work and if needed repin. Also, I believe i still have a spare gps antenna.
Let me know if you have any questions.