Follow this ***exactly***
Use imgburn or similar (
The Official ImgBurn Website) to burn a new (blank) cd with the new downloaded firmware image.
v32 is the latest, but has no updates for the mk4 over v31.
Unzip imgburn, then v31 image and then open imgburn, and select the "write image file to disc" then select the v31.cue or v32.bin file, depending on download.
Select the write speed as the
slowest rated speed for the disc,
you must do this and then burn on a good quaility cd.
When its finished writing your new firmware cd,
Goto the car open the drivers door,
Goto the nav computer and press eject on drive,
Eject the map disc,
Switch ign to pos 1, leave door open.
Insert firmware disc into drive, follow instruction on nav screen.
Wait (approx 6 mins) till sat nav asks to eject cd and reboot.
Eject cd,
Confirm reboot.
That's it.
Do not switch off ignition or close the door when doing the upgrade.
Never ever use nero, and do not use a dvd, it will work, but is not recommended.