Ha I had this problem, Theres two different sizes of doubledin facias I believe "Correct me if im wrong". I told dave@Sere which radio I was fitting "RNS510" and he sorted me out first time :D
 
aftermarket hu are standard double din, uasually 100mm in height. so the cages you get will be the right size to fit the hu, but the opening iin the car varies in size. In order to make the hu fit the cage they have raised bits that centre the hu in the cage, the raised bit vary depending on the cage size.

Koush
 
Hey guys, thanks for all the help and advice.

Koush - Thanks man, I got one of my buddies who's fairly passionate about his ICE installs going to help me out. I phoned him about the cage a minute ago and he thinks he's got one.

But i'll be back if I have any issues.

Going to take pics of the install as well, and will post about how it goes.