Why is it crazy? If you drive around listening to a station and that station fades out of range, then there is (I assume) a list of alternative frequencies being tranmited by that station so that the radio can tune to, so you can continue to enjoy the same station.

As far as I can tell this is almost instant, so the radio will not be scanning for the name of a station as it can take time for a radio to decode the station name, ther must be a list of alternate frequencies

So the question is: If the N900 changed frequency could the radio follow it and if so what is the timeout period for bad reception for the radio to change frequencies. Could there be a delay making it unusable