The only product I purchased from Genos that I didn't like was the windshield cowl vent filter.
I didn't send them back, because I spent soo much time with them, determined to make them work. . I felt too much time had passed.
The fit was very poor - the hood wouldn't close right, cause the plastic pieces wouldn't line up right, the best I could line them up, would cause a section to want to lift, and cause problems on the plastic cowl. Due clearance issues and poor fitting, of the plastic piece that holds the filter in place, I had to put tape on the edge of the hood so it wouldn't rub the paint off.
And because it left the areas around the windshield wipers shafts open, lots of pollen still came in. It was a huge waste.
The right way to adapt a filter to the cowl, is to replace the entire plastic cowl with one that has built in filters and does something about the leakage points that circumvent the filters.
And due to the poor fit and forcing them into place, they pulle on the cowling, and after a month I noticed the cowling lifting and I lost a couple of those pushplug retainers that are used to hold the cowling in to the body, the popped out. I replaced them and it happened again. Finally got feed up with the fit and uselessness of it all, and removed them. Cowl stopped throwing it's retainers after that.