Thank you all for your advise... You've helped me decide to look for a 550i with Nav. It doesnt seem like its worth it to try and add one.

 

Similar to what the other guys here have posted. Hardware wise it is easy (at least for me- but I have disassembled the interior of every car I've owned to mess with the stereo) -- but the software is a major pain. It took me months of scouring ebay to gather parts, three service trips to the dealer, and pulling some strings with some friends at the dealership to get it done. As the others have said, once you've spent $$$$ on the parts, there's no guarantee that the programming head will accept them for use in your car. I jumped into the project thinking it would be easy, and other than the center console controller swap the physical work was, but I'm about $2.5k out of pocket between all the parts and the labor at the dealer.

keep scouring for a nav-equipped 550.

 

Go for it!

There should be plenty of good 550s to choose from; The usual cautions apply ... check the VIN, run CarFax, get an experienced BMW independent mechanic inspection before handing any money over, reserve lots of extra cash for the mods this forum will force on you !