Australian Bushmasters don't have any 'add-on' armour. All the extra protection that has gone on the vehicles in the Middle East has been on the inside (spall liners and such). All the Australian protection upgrades have been aimed at the IED threat. The Dutch wanted extra ballistic protection, hence the appliqué armour. Australia didn't want to compromise the mobility of the platform by adding that much extra weight. Considering no Australian Bushmaster has ever been penetrated by small arms/RPGs etc, it makes sense.
Think you are wrong there Raven.
Multiple reports, photos and videos exist of up armoured Australian Bushmasters both in Australia and Afghanistan (with external add on Armour).
DMO a while ago, reported that the Bushmaster Programme was in the process of adding attachment points for external add on armour to already built Bushmasters.
If you want to see photos:
Defence website had some recently with a clearly up armoured Bushmaster in Australia.
If you have access to Australian Defender, Issue 87 has multiple photos on pages 30, 31 and 35 (up armoured Bushmasters, including close up of extra armour) and 32 (Bushmaster with attachment points but up armour kit removed) in the article "Australian Advisory and Training Teams Afghanistan"
Issue 90 (current issue) page 13 in article on "Operation Highroad".
Or go to youtube and search "Bushmaster CH9 800th Celebrations". At 22 seconds an Australian command version with base armour, 35 seconds you'll see a Dutch Bushmaster with standoff armour kit and at 40 seconds an Australian ambulance Bushmaster with the Australian kit.