im an electronic service engineer mate.
any proven data is going to be very marginal is what im saying.... im not trying to piss on your parade, im just saying things like platinum tipped spark plugs are where there is a real potential gain to be had, at the crucial point of ignition.
anywayz if my engine bay was worth showing i would perhaps do this mod, (myself tho)
Germans dont fack about when it comes to the development of vehicles hence why we all rockin dubz, im sure there wiring is/has been designed to be optimal.
EZ, my 2 cents