It is, but the trouble is the kit required to do direct injection cars is not used by the dealers.
I've tried contacting terraclean saying they've ripped me off, but they won't respond to my complaints.
It will clean your fuel system, but not your inlet valves where the problem can arise on our TFSi engines.
I had this done, then a few weeks later had an injector changed, and was told that my intake was well n truly gummed up.
terraclean did nothing to fix this, and that was why I tried it.
I've tried sending the picture of the gear needed that terraclean say they have for doing direct injections, but no dealers keep it.