Before the 2009 facelift, the navigation system was only available as the Multimedia option which included the screen, nav, reversing camera and Mark Levinsion audio upgrade. After the 2009 facelift you could still opt for the above, but there was also a cut down version, giving you the nav and rear camera system but without the ML sound system. This was known as the ‘Full Map’ option. From the 2011 facelift, the Full Map option was the only option remaining as the ML system was dropped from all models apart from the ISF. There will be some ‘11’ plate cars around with the ML system but they will be pre MY11 facelift cars registered in 2011.
It is possible that the 2009-2010 SE-L were only available with the full blown Multimedia system and the Full Map version was reserved for the lower spec grades.