You are likely suffering a leaking valve cover gasket if you are noticing oil leaks down the side of your engine coming from the cylinder head. With age, the soft pliable rubber becomes a brittle, hard plastic. This causes the valve cover gasket to lose its seal and allows oil to leak out of the engine.
About Elring
Elring was founded in 1879 by Paul Lechler. Elring "the original" is their trademark, because as an OEM (Original Equipment Manufacturer) to so many automobile manufacturers, there is a chance Elring provided the original gasket. Elring is widely known as an OEM replacement provider of quality parts for European model vehicles. They are mainly producers of gaskets, seals, and other high end supporting components. With locations around the globe, Elring is already established as one of the greatest producers of parts for European vehicles including luxury makes such as BMW, Mercedes, Audi, Volvo and many others. Elring - "Das Original"