Changed my rear rotors and pads today and noticed a metal v shaped clip connecting to a little hole on the top of each pad. But I only had one on each side.
There are 2 more holes at the bottom where either its for another clip or the hole for the clip would be on both sides regardless since it doesnt matter which side the pads are on. Im going with the later just because old pads wore uneven.

Do they sell these at an auto part store or do I have to get this from mazda.

Sorry for the double upload. Did it all from the phone

I know when you buy aftermarket brake pads from autozone they come with them

Tried Bennett but they didnt have them. Autozone ended up having them. Comes with the retainer clips for 8.99

The "V" spring is only used one per caliper and goes on the lower end of the pads.
Thus two springs is all that is needed for the rear brakes.

Page P-27 of the FSM.