Gonna have to agree with Larry on this one. A diesel engine "messes" with it's OWN air to fuel mixture constantly. It will gulp air all it wants. The reason a turbo makes such a difference (in a nutshell) is because it ALSO increases fuel flow at the same time. ( they talk to each other you know..the turbo and the injection pump. They speak "clatternese") Anyways, the only placement change I would make is if your air intake is getting water in it from?????who knows maybe fording a stream that is to deep? Flooded roads in the spring, whatever. I have often thought about putting a "snorkel" on my Rabbit to get it higher. Then I realized that when you get in water up to the door handles, the rear end comes off the road anyway so what's the use? I would think that by being behind the headlight assembly it would give it a little protection from the elements as well as giving it "fresh" air to breathe.