Thanks for the comments Guys,
I must say that I am a little dissapointed with CD based navigation. I am in the UK and it only seems to work on major roads, even though all the streets seem to be in the database. It usually drops off quite a way from final destination, just when you need it most. It would be interesing if anyone else had any comments about this. Lexus dealers do not seem to be very knowlegeable, or even know what map updates are available. Mine is based on 97 data, possibly this is the problem. I have ordered a new one, which will be here "sometime".
Mike