This past weekend I went to replace the cabin air filter in a relative’s 2013 Versa Sedan. I had ordered the filter beforehand so I had it in hand. When I got under the glovebox I found that the car had no filter in it, just a cover on the space where I thought the filter should go. There was no way to install that filter without part of it hanging out. I went back to several parts sites to double check the filter I had. The filter appears to be the correct part but I saw a note on one of the sites stating that not all Versa’s come with a cabin air filter. It depends on the trim level. That sounds very shaky to me. There is a space to mount a filter. I will not get into why Nissan would cheap out that much to not include a cabin air filter, but I would like to know if I did manage to find a frameless filter to fit the opening & I did install it behind the factory cover would that be opening up a different set of problems ie would a filter overstress the fan motor so it could possibly fail? Would a filter restrict airflow so much that it would adversely affect heating/AC/defrost effectiveness?