If you already have Aero 3 or 4 mirrors, you can improve the grip on some vehicles by purchasing alternative pads. If you have Aero 1 or 2 mirrors, you will need to replace your clamps with new Aero clamps 4589, or upgrade to the Platinum range. Platinum mirrors do not require any additional partsThe 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.