After weeks of trying to find a rattle coming from the rear right hand area, I have finally arrived at the conclusion it's the brake pads on that side that the rattling in the calipers. The rattle is very loud when driving on rough roads at low speeds and I have found that if i put my foot on the brakes the rattle goes away completely. The hand brake has NO effect, so it's not the handbrake linkages. ( which I have already isolated with rubber tubing ).

I found that on the quiet side, the inboard brake pad that is pushed directly by the piston has what looks like an anti-rattle spring attached to the back of the pad that clips to the insided of the piston, but on the noisy side there is no spring attached to the inboard pad. It looks like the sping is welded onto the pad directly and is part of the pad not a later addition. I am assuming then that the noisy side has lost it's spring sometime in the past - do all rear brake pads have this spring on the inboard pad ? If not, I need to make sure that when I order new ones that I get the correct pads with anti-rattle springs attached.

has anybody changed the rear pads recently, and did you notice a small locating / anti-rattle spring attached to the inboard pad ? The photo attached clearly shows the spring so I guess I just have a faulty pad.

I have found that I can rattle the brake pad around in the caliper and the sound is exactly the sound that I am hearing when driving along, so I am now 100% sure that this is the cause of my rattle. In trying to find this annoying noise I have already replaced the rear springs, upper and lower shock bushes, roll bar bushes, isolated the park brake cables and linkages, replaced exhaust mounts etc. To find it's just a $40 part is very annoying.

 

I changed my brake pads a few weeks ago with non-OEMs. Yes, they did have springs (more like twin arms as your picture shows) that were permanently attached.

They fit tightly into the calipers and thus no rattle. This is for the non-Brembo brakes on a 2001 MY.

 

I experienced same problem with rattle. We traced it to incorrect rear brake pads being installed.These were replaced with correct fitting pads and the rattle was eliminated.
Rob Seignior,Australia 1997 BRG XK8 4L coupe.