Picking my jaw off the ground!!!
Yeah I thought maybe the bag was in there at first though. Then second thought and said nah he just meant dirty filter as it looks rough itself and bag is unrelated to issue and was the bag new filter came in. HOLY CRAP never in a million years would I have guessed a bag could make its way through the intake to the filter. Be glad the filter did it's job or well I think we all know what would have happened.
OP - I would recommend changing the filter a little more often as that filter looks way past its life span in general. Also would recommend K&N drop in filter. As they last longer and can be cleaned, re-oiled, and reused. Just my .02/advice.
(11.)2012 GT500 silver with red stripe, SVT performance package, and Recaro seats.
2018 Honda Civic Type R
Past Mustangs in order and color of text.
(1.)2000, (2.)2004, (3.)2006GT/Auto traded for (4.)2006GT/Manual, (5.)1996, (6.)2011GT, (7.)2003GT, (8.)2006GT, (9)2013 Boss 302, and (10.) 2002GT
(I have owned a few non Mustang cars over the years as well, but always try to have a Mustang with it or come quickly back to a Mustang!)