They are not anti rattle clips, they are retaining clips. If they are not in place or if they are installed incorrectly the pads will not stay fully in place and can cause a low brake pedal. In extreme cases it can cause one hell of a rattle as well, sounding like a broken axle.
I have seen this more than once, I even installed them wrong once myself on my sons car and got it corrected before he backed his car fully out of the driveway.
The ends of the wire spring clips must insert properly into the holes in the caliper and the spring clips must apply tension on the pads to hold them in place or the caliper piston will be forced further back into the caliper after releasing the pedal causing too much pedal travel.
Don't mess around with it. Get it fixed. It is a safety issue. Find another Contour to look at (one that is properly assembled) to see how the retaining clips need to be installed.
