My original 2003 M45 does not have navigation (I did not spring for the package!
)
So, I use a Magellan 3597LMT unit ... this is absolutely an awesome navigation unit, albeit far more clumsy since it is not built-in. Has a 800 x 480 5" color touch display that is a beaut to behold and use. Completely voice-command driven, which makes it very easy to use.
It comes with life-time
free map updates for the US. So, just about every 3 to 4 months, I plug it into my laptop, download the latest maps and all is well! I use it for travel too ... will pay for itself soon enough avoiding the daily fees that the car rental guys charge!
I also sprung for a set of Europe road maps (cost is $99) one time, since I rent and drive there occasionally, and now I don't have to pay the very high navigation rental fees there either. This is most useful, since I am not familiar with the roads there as much, of course!
One time, the Hertz person at London's Heathrow saw my unit, sighed and threw in their navigation for free for the day I had the car (it was a built-in unit in a Merc that I was given and he couldn't turn it off anyway, I suspect, but would have charged me for it otherwise!). That was good!
Z