Just a very big Thank you for all the comments in this thread. I read and read and read, but with the pictures and taking my time I successfully got this installed and configured. I have only a few minor bits of advice to add.
1) Before you disconnect the battery, if you have a power drivers seat, move it back. Don't ask me how I know
2) Take out that panel under the drivers seat and tie it up to get more room for the body control panel connector. Especially if you need to splice the purple wire in.
3) I have a 32 gal tank, the body harness from the tailgate to the front runs above it. pretty tough to zip tie that to the body harness since you cannot reach above it. so I could not do the 150 mm thing there. I guess this is just a warning for those that have a big tank.
4) No where in AlfaOBD could I find 'Trailer Hitch Camera'.
That's all I can add.
Thanks again for this great thread.
Monty