Hi Drew, I didn't solve it. Tried all sorts of things behind the plug to hold it in position.It was either throw the car away or get one of the Android head unit, since you can plug the connector in without those locating clips.
The one I got was expensive at the time, and it was a little under powered to run lots of apps. I looked at them a while ago and they seem cheaper and more powerful now.
It was a good upgrade, bluetooth etc since the original (BA) didn't have it. So I was happy with it in the end. Still driving the car almost daily now.
It's been in there for about five years now. The only mystery thing I have is the rear parking sensors just stopped working one day, can't see how that is related to the head unit though.