Hi
Sorry for the delay in replying - Christmas and things took over for a wee while!!
I came here on an ETA and applied on-shore for the 835 LRR visa a week later. I applied for working rights at the same time and was asked to complete a hardship form. On this, I explained that I was in the country with virtually no money or assets and that whilst I was planning on residing with my parents and that they were fully understanding in having to support me, I didn't want them to. I wrote on the form that they are 'self-funded retirees (which is the phrase they like as it clarifies that Oz isn't giving them any money!).
I was able to start work once the 3 month tourist visa stamp had expired and my Bridging Visa started.
One note of caution for this is that your son should keep all copies of all paperwork and record the name of the person who sorts out his Bridging Visa. Once I was allocated my CO, I had to prove that I had been given working rights (right hand/left hand!!). I was able to do this quickly as I had requested a passport label (which they don't give out as a matter of course).
I had posted out paperwork prior to me flying as I was worried about getting stopped at customs and trying to prove that I was only on holiday whilst having a suitcase full of my life and discs with my cv on.... I wasn't stopped but I certainly felt more comfortable knowing that my health records, banking paperwork and work references were here waiting for me...
I didn't front-load my medical or police checks due to immi being able to date these and then somehow prove that I had entered the country under false pretences...
I have had my application in since November 2009 and am still waiting, but at least I am here and working and getting on with my life....
Let me know if you need any further help and I will do my best. It's not an easy process emotionally or physically, but it can be done
Cx