I suppose anything is possible, but adding nav would be prohibitively expensive, if it's even actually possible.

BT can be added to certain production date MY04 cars with a software update (for earlier cars you need to replace the telematics control unit which as I recall is over $1,000)--it was discussed within the last week or so--do a search for details.

 

No, you can not add nav. If you haven't noticed, the nav cars have a completely different idrive screen, and have a dvd slot below the cd slot for the nav dvd, and the dash is laid out different to accommodate the nav components behind the dash. Look at some pics to see the difference between nav and non-nav cars. Not just the screen, but the center console as well. After market system (like a garmin) is your only option.

 

My Service Advisor told me that it is not possible. However, she said BMW will offer a retrofit kit beginning this summer that will work.

 

I believe there was a limited production period in 2004(January 04 to March 04) where there was some prep from the factory that would allow for a NAV retrofit. At the time it was $1800(the same price as the option). I don't think factory NAV was available in any E60 until March 04 production.

If I recall correctly, the way to tell if the vehicle had NAV prep is if your non-NAV E60 has both a menu AND voice button with the idrive knob. Regular non-NAV E60's only had a menu button.