Mix ratio of fluids for windscreen washer system

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2013 Porsche 911, 2012 Porsche 911, 2011 Porsche 911, 2010 Porsche 911, and 2009 Porsche 911. However, it is still accessible from the selected car via links, so may be relevant.