| March 2003 on builds have DVD drives. You can buy either a CD or DVD map disc for those units. CD is about £120, DVD is about £200. CD's have all of Britain on them, DVD's have all of Europe.
The firmware update disc is something totally different and you can't buy this. Your dealer may update your system for you if you ask them nicely. Alternatively, there are often CD images of the update CD available for download on the internet if you look hard enough. | 
