I had thm fitted to the MK5 Golf, and it was possible to fit them without taking the wheels off, you just need to adapt your tooling. I used a 3/8" socket arm, the appropriate torx bit and a socket small enough to snuggly take the torx bit - just enough room between the wheel and the arch to get the socket arm in (fronts are easier when you put steering to full lock. Would I buy them for the Roc? Nope - £150 for the set??? The MK5 Golf ones were £56 for the set of 4.
I can report that I don't have stone chips all up the side of my car (as VW used to claim mudflaps helped prevent).