WARNING: This page is about a different car, the 2010 BMW 550i, 2009 BMW 550i, and 2008 BMW 550i. However, it is still accessible from the selected car via links, so may be relevant.
Order number: 13 6 058
T-piece for 12 mm dia. line
Fig 1: Identifying T-Piece For 12 mm Dia. Line (13 6 058)