After jacking up the car and seeing that the diff was only bolted to the boot floor and moved all over the place we decided to strengthen it.
We found some steel channel and used that to fabricate a H section that was secured to the inner wings and the rear panel, and bolted through into the diff mount.
This has tightened up the whole bootfloor and diff mount.
The spraying job wasn't too brilliant I must say, but then again I'm not that great at painting.
Fabricating of the diff strengthener:
Test fitment into the car...