Scionlife.com - Need Help Identifying a Part

Hey everyone.
As a bit of an introvert I mostly avoid posting to forums and talking to people in general, but I'm kind of at a loss here.
I recently had some fender liner damage in my driver's side fender. I replaced the liner entirely with one I got on eBay, but I noticed something a bit odd...
First of all, the liner did not sit flush with the fender itself, mostly towards the top of the liner. I figured maybe after some time and exposure to the weather would change it. Unfortunately I was not able to see it last long, as it was caught by a gust of wind which in turn popped it out of place, and was ripped off/thrown into the air by my tire while driving. So this leads me to believe it probably wasn't a OEM grade replacement part.
I did notice however that it was missing a part that my other fender liner has, that bit in the front. I don't know what to call it or even how to search for it, so I've included a screenshot with it circled in the illustration.
Any help/recommendations would be appreciated. I've been in a bad spot in life lately and just want to get this thing taken care of before something winds up getting damaged.