I am reporting only what I have read in other threads and do not remember anyone reporting that they tried a disk from another geographic area. Assuming that AUS = Australia and not Austria, I checked and there are Australian Lexus DVD disks on ebay but they are expensive: http://cars.shop.ebay.com.au
It is possible that the Australian disks are not compatible with your nav system due to the region code being different.
Hmm well his gone buy the disk then . About the region problem i was thinking the same thing but read on a EU forum it was just a matter of connecting up the right region DVD reader.
Can not understand why Lexus made such a dumb system that can be messed up.