Thank you all for your prompt responses - very impressive! I suppose I shouldn't be surprised as we all chose to own a Lexus, and are therefore of keen judgement!
I read the thread about the new DVD forcing a route through Central London.This is not isolated to the new DVD. My 2001 LS version always chooses a route through Central London as opposed to the M25 etc. Strange as, when I travel between Manchester and Wirral (which I do alot) the choice of many different motorways around Manchester and the M62 to Liverpool and M56/3 to Wirral always seems to be flawless and agrees with Autoroute etc.
Maybe Central London holds a strange attraction for SatNav units!