Retrofitting AMI, is it possible?

I have a 2005 A3 and I am hoping to retrofit the AMI unit. With it being an older car I do not have the right CAN BUS Gateway module. Mine is the D revision. Can anyone help in telling me the right revision I need to get the AMI working so I can hunt for one on ebay or a breakers yard.
Thanks
 
Sorry to butt in, but what would I need to view tv and/or DVDs on-screen in my new S3 BE? It has MMI, Nav.
 
Would anyone know if an AMI from an A5 AMI 8T0 035 785 can work with a 2011 RNSe in a 2007 A3?

I know it sounds like a mad mix!