I just installed my fenders strakes and I had problems at first removing the plastic clips. Here is a very important picture I had to submit cause it helped me understand how they work...
I broked one before seeing this picture. Here it is:

 

these are found all along the fender liner and undertray.

sometimes they're a pain in the ***.

i have extras just in case. lol

 

Yup, $1.98 from dealer. Don't ask how I know .

Take care,

Brian

 

I have a couple of dozen of those things in the garage after various buys and/or mods.

BTW.....Not that it is really needed because all you have to do is a little turn to the left and the center pops out but this is my favorite tool for removing these. This will then slide under that outside piece and remove it cleanly.
.........sorry about the lack of focus. I don't use it all the time because it's really not needed but sometimes that ooutside piece is tough to start to ge lifted and pulling on the pin(after lossened) doesn't always work.

 

when you know how they work, it'S really easy!

When the head is clipped off using the + screwdriver, I can easily remove them using my fingers...

 

seriously, they can be done by slowly unscrewing the screw, while also applying more than normal pressure in towards the screw. the screw part will slowly lift from the rest of the piece, where you then shove something in (like your finger) and pull the screw the rest of the way out which will then allow you to pull the whole piece out.

the trick is to turn SLOWLY while applying inward pressure.

 

Is it a quarterr turn to the left and pull out from the base of that plug? At least that's how I've done them in the past. You guys making things more difficult.

 

yeah ***** easy... if you need another one of those they sell them at pretty much any auto store.

 

quarter turn to the left without putting pressure on it and it would pop out then you pull it off with our fingers

 

and if ur still having trouble, just hold the outside ring while u twist then they wont move together!