Just because this is old and to post a couple of things I'm not sure are included in the previous pages;
They did upgrade the intake for the mk6 Golf R with the DV relocation...
.....and the Volant did result in low fuel trims, on average, when they had MK6 Golf R people report their fuel trims with various intakes; on another forum. This averages were posted once ten people reported for each of these intakes. So some didn't make their list if less than ten users reported their trims;
I may have posted this all before, on those previous pages, but I'm old now (62 next month), and I just don't remember.