There are three software versions for '04-'05 Mazda navigation units (CN-VM4360A). The first was U9.95 2003.1. This update is the second one, U9.136 2003.7 released in 2003. Thanks to maverick02 of the RX8Club for providing this update. There is one final update I know of (U9.139 2004.1) released around June of 2004. If anyone has a copy I can host, please let me know.

Step 1: Download this ISO image and burn it to a DVD-R disk. The nav system does not recognize any other format.

Step 2: Turn the car ignition switch to "ON" or "ACC" to power up the navigation unit.

Step 3: Open the nav cover and eject the map disk. Insert the update disk. If "Old Upgrade Disk Re-insert Map Disk" appears it means your firmware is already at or above this version.

Step 4: Wait a few minutes and you'll see this screen. Re-insert the map disk and you're done!

Note: This firmware update may only apply to North American nav units. I've been told it does not work in British ones.