HI I HAVE JUST BOUGHT A LEXUS RX300 03 AND THE SAT NAV DISC IS VER 1ST 2002 86271-24121 AND UNDER THAT NUMBER IT IS 86271-70V311A WOULD LIKE TO UPDATE AND I HERE U CAN GET A UPDATE DISC AND A NEW MAP DISC IS THE TRUE AND IF SO ANTONE NOW WHAT I NEED AND HOW MUCH HOPE CAN HELP MANY THANKS