Face it toward the front. Look at your air filter and you'll see why.
Dirt comes in the front of the car. The shield on the breather cap helps to keep it clean a little longer. I'm guessing you have something like the K&N element style breather.
Depends on the type of "shield" you're referring to. I'm guessing one that attaches on top of the valve cover? If it shields the breather that is stuck into the top of the valve cover it should face towards the front of the engine. The idea is that the fast-moving air from the fan could cause a venturi effect, causing engine oil to be "blown" out of the breather and all over the firewall.
Another type of "shield" is a piece of metal inside the valve cover. These are usually welded in, or part of the valve cover and not positionable. They shield the breather from direct oil splash off the valve train.
Am I close?
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