Hi All,
I've been looking for another option to run power cables/boost gauge lines from the engine bay into the cabin, to avoid drilling, and I think I've found it...
On the passengers side, inside the quarter panel there are two grommets leading directly into the footwell (one would presumably be used for the bonnet release cable in LHD vehicles). They can be accessed by removing the guard lining and popping out the indicator for a better view.
They come out above the fuse box and wiring harness.
I ran 8 gauge power cable in the flexible plastic conduit stuff along the top of the guard next to the indicator wiring then into the engine bay.
It's a straight run through the grommet too, so it would be ideal for boost gauge lines. This square-ish hole is directly behind the grommets.
Hope this helps some 6 owners