Nav screen would probably fetch about $600 to $700 (example -
http://cgi.ebay.com/ebaymotors/BMW-B...m180242385429& )
The MkIV nav drive would probably fetch about $550 to $650 (example -
http://cgi.ebay.com/ebaymotors/BMW-M...m270237046487& )
Keep in mind that if you remove your nav unit then you'll lose the ability to update and control your on-board computer functions, date, time, etc.