Hey mate, sorry for a late reply, I've been busier than a one armed bricklayer in Bagdad.
Basically used a Narva flush mount, like Macca's. I just happen to spot it in an Auto parts place while I was in there. Power source is taken from the spare plug in the dash that people use for GPS. I just cut down some spade connectors to fit in the plug slots & fitted a 5 amp in line fuse to be safe.