I installed the BD 2 Low kit on my 2013 with the G56 manual transmission. It works great and has eliminated me having to constantly be on the clutch during tricky back ups with the trailer. It will definitely extend my clutch life.
I didn't want to drill the dash either so I bought a single switch bezel and reamed out the opening to accept the switch on a friction fit. I then ran the wiring into the storage area in the bottom of the centre of the dash and mounted the bezel in there with double sided tape. It is easy to access, hardly visible, and no holes in the dash!