My window visor is made by EGR Australia and it's only supported by 3M double sided tape at the back. It's the slim type one with an embossed EGR sticker on it. I'll post pictures of it soon.
There's a whistling sound depending on how low your windows are. I had one side of the visor come off when i was cleaning my window but the tape still holds. I already bought 3M double sided tape just in case i need it in the future.
EGR Automotive Australia Home ? OEM quality moulded vehicle part manufacturer