It can be done, I think you might have to make custom engine mounts...
I know there is a guy with a 1.8t Rabbit. John Pastore. I saw a few videos of it.
Check out
www.rennen.us there are a few pictures of it there.
Ok, I just found this. Go to
www.vwvortex.com and look up a member named "Johnnyturbo" This is John Pastore, If you are serious, email him and ask about the swap...
If you aren't allready familiar with
www.vwvortex.com then you should sign up, it is a good site...
Hope that helps,
Mike.