Ive had another look. There is a bolt in the fusebox area (I think it might be the same one that was in my 7.5) but it is now inaccessible due to a plastic trim which covers the lower part of the fuse area.
Its just below two relays marked 646.
Ive tried to show where but will take a better photo when the light is right.
If you take off the panel at the end of the dash with the passenger airbag off switch in it, you can bolt an earth to the metal structure of the dash. I also used a fuse that is only live with ignition on