The car leaked oil for years. I never knew where it was coming from, but since oil was all over the engine it makes sense to start at the top. I replaced both valve cover gaskets. The old ones might still have worked if I just tightened the screws holding the cover down as they were not even hand tight. I think replacing the gasket has fixed the leak.

Very surprising the valve covered failed so early in the life of the car. We replaced it on our own and it was quite a pain to do so. You have to remove the entire intake manifold and a lot of hoses and parts. Most of the plastic on top of the engine is incredibly brittle and will just fall apart in your hand as you remove it. Overall we replaced the front and the rear and are no longer plagued with leaking.