i just purchased a 2003 e500. i want to buy a new command with navi. my question is do i need to update anything else besides the new navi command unit?

 

Depends on whether you have a US spec car, or a ROW the world car. And if you have a ROW car, it depends on when the car was manufactured...

BTW, just retrofitting a DVD comand in your dash doesn't give you the navigation function in a W211. You would also need the nav.drive that goes in the trunk.

greetingz,

BigSis

 

isn't the new 2006 navi command one piece with the build in drive?

 

no - not for the 211

greetingz,

 

Here are some picture of what it looks like:
https://mbworld.org/forums/e-class-w211/100143-oem-navigation-retrofit-w-pics.html

Steve (MBenzNL) can set you up with an install.