Silkrip

When I received my slightly-used 2017 NSX, the little card containing the anti-theft codes for the nav system and audio system was not in the glove box. This worried me, because I wanted to disconnect the battery to add some accessories (like the NSX battery charger and some other items). Well, it turns out, that not only can you retrieve the anti-theft codes, you actually don't have to.

Retrieving the Anti-Theft Codes
Navi > System > Detail Information > Settings > About
This gives you the 8-digit serial number of the Navigation Unit. With that and your VIN and your personal information, you can go to owners.acura.com, select "Quick Links" and select "Retrieve Navi/Radio Anti-Theft Codes". Enter the requested information including that 8-digit serial number, and you get your unlock code (5 digits). Simple. But also unnecessary...

You Don't Need the Codes
If you have disconnected the battery and then re-connected it (and be careful about door opening/closing during that process!!!), then you can restore the navigation system and the audio system to functionality by holding the power button down for > 2 seconds. What apparently happens is that the Nav System communicates with the master control unit in the car and, if the master determines that the nav system is the one that originally came with the car, the functionality is re-established. Clever.

Silkrip

Well, I disconnected the battery so I could wire in my race computer. After reconnecting the battery, I turned the ignition on. The nav system came up with a notice saying that power had been lost but the nav system could be restored to functionality by holding the power button down for > 2 seconds. I did that, and everything started working just fine. Very civilized.