Zwnav Firmware [top] -

Adds support for newer aftermarket accessories, including AHD backup cameras, TPMS sensors, and OBD2 diagnostic dongles. Step-by-Step Guide to Updating ZWNAV Firmware

A Russian forum that is widely considered the "holy grail" of custom and stock firmware for these devices (requires a translator). How to Install the Update (Step-by-Step) zwnav firmware