I have a AU 3 Premium head unit and amp etc, what tricks do I need to look for when fitting into my ED.

Thanks

To be honest, I would be selling the AU unit and buy a nice unit from someone like JBHiFi, they have some very good deals running right now with units and Speakers, check them out http://www.jbhifionline.com.au/ or Supercheap, they also have some good deals running.

All the effort to install into an ED I believe would be wasted and you would be very disappointed when finished, sorry...