Mmmmm .... well, the way the town and highways planners in the UK change road layouts, put in traffic lights, roundabouts, re-prioritise junctions etc, we need updates every month.

The Navteq updates are at least 12 months behind 'real world' and they also have a habit of undoing updates - I speak from experience when my street was 'un-updated' in the 2006-1 DVD and after ranting at Navteq, they updated again for 2007-2 (street name was wrong)

However, our house was built in 2001, and they STILL haven't got our street numbering correct in 2007-2 dispite about 10 bug reports to them. Our house and about 10 others just don't exist - the house numbers jump from 18 to 36, and whilst there are natural gaps, if you select our house number it fails to find it and jumps to 36.

Oddly enough, my wife's Nav in her Toyota Prius is spot on, and that uses Navteq map data, so I am inclined to think that BMW don't pay Navteq for the very latest data, but charge an excessive amount to their gullible customers for the 'latest BMW map updates'