Hi Arno, yeah I presumed there would be one on the front connection if there was one on the rear..
The front looks to have the same rivnet insert as the rear, and a flat terminal connection, therefore the contact wouldnt be that good presumably. I can't see if the anodization has been removed, but either way, without the stepped washer, it would just be connecting to the rivnut.
All my starting issues appears round about the time I fitted a different exhaust, and mucked about with one of those battery isolation terminal (with the screw knob) on my already dodgy looking negative terminal / earth strap.
Other question - I've changed the front battery negative terminal (easy enough with a section of earth wire and two flat terminals), but where does the positive battery connection go to (item 6)? Looks like it disappears under the windscreen or into the sill somewhere..