Look what I found while replacing the transaxle in my Prius. I wasn't looking for it there if you were wondering. I had some time to pop these out. Took less than 5 minutes to get them out once the wheels are off. There was a few pounds of crap lodged in there. I carefully scooped out as much as I could and then hosed the rest out. Found a rust spot and bubbling paint which I will repair before undercoating it.
To remove the plastic clips, Pry under the inner disc with a smallish slot screwdriver or pry tool till it pops out about 1/4" then pry under the main disk and it should pop out. These are re useable. The rest of the screws are 10mm.
Nip this in the bud and your car will last many years longer.
Nasty
Nice:
Don't forget to clean under the fender lip too.
I plan to do the back fender wells also and seal them off better so this does not happen so quickly