Talk to the people at tischer. Get the full retrofit with the TCU. Going w/ bimmernav and their route is a recipe for disaster. Just because BMW assist is installed doesnt mean you have to activate it (you get 4 years free from date of vehicle purchase).
2007 328i (01/07 Production)
Blacked out Kidney Grill || Bluetooth Retrofit || Ipod Retrofit || Rear Power Outlets || Euro Switch || Blacklines