Milenco Aero Towing Mirror F Pads (Pack of 4)
The Aero F Pads have twin grooves for enhanced grip on typically VW group cars (Audi, Seat and Skoda) post 2013.
For the Vauxhall/Opel Astra 2016 models use the Aero 3 Mirrors and F Pads. see image
For BMW X3 use the F Pads and mount on the top of the mirror housing. Alternatively you can use the Falcon Mirror Clamps part number 4220. Do not overtighten