Out of curiosity
Every 328i or 320d that i have seen as "demos" or that dealers have in their lots all seem to only have the business nav - Why would they not order the prof nav on their demos and avoid to have to order a new car?? - imo once you've seen the prof nav there is no going back.
When ordering my 320d, they kept trying to sell me a car in the lot with business nav, no way that was gonna happen - like going from a 50" plasma to a 32" and telling you it the same picture.
Same goes for seated heats - i had them in my 2009 Z4 and could never go back to not having it - especially if you suffer from any sort of back pain or muscular damage - highly recommended