i think it depends on the build date, but if you're rocking a 4:3 screen it's a mk2. I swapped out to the widescreen on mine and never upgraded the navigation to mk4. I bought a dynavin unit instead and never looked back. Best idea ever. Dropped a G total including install and replacement amp, but sold all of the other junk i no longer needed. Best bang for your buck. Sorry to resurrect, but trying to find download links for an mk2 navigation CD for a e65 (wife's new car and she hates me that it doesn't have nav)