The owner's manual doesn't say much at all about the nav system, but refers you to the 'supplement', which didn't come with my car. I see they are available for about twenty quid, but that's a bit steep just for the odd query. Mine is that I can't remember how to turn the voice on and off. I did it ages ago but forgotten how! Fed up with the woman telling me to 'observe the speed limit'. Spose I could just slow down! Anybody help please?