Beatup/Missing Plastic Underbody and Fender liner Repair

Evidently lots of us are faced with this problem. The car really DOES need to have those parts down there, and they are flimsy and don't stand up well to road debris, snow buildup, etc. Without them, the car loses aerodynamic sleekness AND road dirt splashes up in places it shouldn't.

I am having a hard time figuring out the part names and numbers of these various plastic things, what fasteners they need, and good places to buy all of the above - thus this thread.

I have a 2010 Gen3, and today I bought a new rear bumper cover and it occurred to me that I am missing a whooooole bunch of those little plastic components down there and I so far I have found little bits and pieces of info here and there, but I still need more ; )

 

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i think it is this one--->

And rather than a purchase link that will work for a month or two, here is the search that found dozens of them. The kit in the video looks like about 15-20 bucks average. http://tinyurl.com/ycga9b7m