No guarantee it "works great". When a vehicle manufacturer (like BMW)has a fluid (like antifreeze) formulated for a vehicle. The fluid manufacturer is given a list of materials the fluid will come in contact with, and therefore is required to NOT interact with or degrade. Throwing non-BMW-approved materials at the problem is hardly "I came up with a better solution to the problem" post worthy. FWIW, whenever I shop for a vehicle and see things such as this, I run! If I can see "shoemaker" repairs on inexpensive items first glance, I wonder, what other hokey repairs have been done on the vehicle?