I just read the winning entry [http://prospect.rsc.org/blogs/rsc/italianjobentries/winner.pdf] (PDF) and it makes sense. One thing to note, though, is that only the middle windows on each side are smashed out; the two on each side toward the front are smashed in while leaning out the side, so that you don't lose the weight from their glass.
Also, apparently Charlie was lying right on top of the necessary access panel in the movie; all he'd have to do is pry it up and he can reach down to get at the fuel tank.
Well done, Mr. Godwin! Mr. Bridger will be pleased. Enjoy your holiday among the angry, stirred up Caribineri and enraged Mafia!
-- Steve