Should I care about rusted-out brake dust shields?

Do those "shields" help with directing air into the rotors for cooling? 

I'm curious what the "shield" is shielding.  Surely not dust.  Maybe something else?  A road hazard?? 

I would think that if they were not necessary, the manufacturer would not install them.

DON'T think that is a TOYOTA PART! If you have DUST FREE PADS from CENTRIC or other you do NOT need SHIELDS! 

Leave it alone.  It is just a cover.  It is not an integral part in your car.

It is strange yours are rusted out.  Most are not.  It is not a big job if you have the right tools. Usually the rear have drum brakes so there are hooks and loops springs hook into to make it work. No dust shield means no rear brakes AT ALL. Really have a mechanic assess the situation.

Just break them off by bending them or use a sharp chisel. If you have drum brakes in the rear I'd leave them alone.

Why no; no you should not.

On a POS old Toyota, no.

They are only there to keep road debris from being thrown up into the brakes.

If you drive on paved roads it's not a issue

I have no idea about the set up in your auto, in my jeep however. The dust shields are also the mounting for the e brake, so when they rusted out. They needed to be replaced.