Got the wiring all ready - its green with blue for the switched 12v+ on and run. Gray and REd for the dimmer - Brown is ground - found a rubber grommet in firewall to put the hosing through - fed it up to the back of the area for the gauge - should be here soon and will be cutting the hole in the dash cover.
To get a mounting spot that will be flat and stable you have to grind off a tab on the back and some of the mould casting bumps on the aluminum. Can use a grinder to remove it but be careful of the heat - doesn't get as hot as fast as steel, but can get VERY hot slowly and if you melt the vinyl covering you will not be happy. At least I didn't cut the hell out of any that one can see
Have measured hopefully for best placement of gauge and will cut final hole in cover with a hole saw drill - same as doing a door knob in a metal door. Have to cut the covering so the it can be folded down into the hole to get a great seal around the gauge. Will have to cut a box out of the dash under the cover as well.
Will show how next post.