Hi everyone. I have found the navigation function on my MK3 unit fitted to my M3 to be near useless without postcode searching. I really need to upgrade to a MK4 unit.

I have the BMW television function and telephone kit installed which work through the unit. Will I lose any functionality?

When I spoke to BMW main dealers they thought it would not be a straight swap but online research seems to think it will be.

Can anyone give me a definative answer? How easy is fitting?

Many thanks

Neil