Fitting straightforward and looks quite good for my car. Minimises draft when window open at low to medium speed.
Can impact view to driver when looking to the right at junctions and roundabouts so need to be extra vigilant in this case for approaching traffic.
Certain limitations when washing / drying windows at top including inner surface of deflectors.
Not sure wind buffering is totally eliminated.
Main reason for purchase was to enable increased airflow when transporting 2 dogs in warm weather.