One thing that comes to mind is that the digital radio signals don't operate in all areas. Maybe its because of the vastness of Australia that we don't get that option here. In buit-up Europe I would imagine that digital radio is everywhere.
Mind you, if the unit offered AM/FM as well as digital then that would be a different matter. Also, how would it be installed if you have an integrated SATNAV/AUDIO system, there'd have to be a certain amount of "software" reconfiguration for the unit.
Assuming that its the same as the Toyota implementation of DAB on the Prius, it should come up as a separate input/band along with AM / FM etc.
Here is the link to the Lexus EU option : http://www.lexus.eu/.../equipment.aspx
It seems to be dealer fitted option: http://www.ct200hfor...dio-module.html in the UK