I have the OEM deflector but just by looking at the exposed hardware on that Cabrio one there ain't no way that is going in my car. I have full leather and one tiny slip the head of the bolts or that weird looking pin would not do nice things to the leather that is all around that area of the car. It also has a funny shape to it in the picture of it up, looks huge. The OEM top you can easily install has rubber ends and plastic. It also can be lifted up or down while driving, not sure about that other one but it looks like it has some sort of thumb screw. Hate to say it but I know the price is steep but I'd go OEM.
For the OEM part; Yes it fits all 8 series convertibles. Deflector Assembly - BMW (54-34-7-443-147) I've seen OEM price at 720 before.
https://www.bmwdirectparts.com/oem-p...YaAmNdEALw_wcB