The possible causes of the rattle in the rear tire are loose lug nuts. You should also Check your shock or the upper shock mount. There are various possible causes to this and so you can check the rubber in the sway bar linkage and contact your mechanic for more troubleshooting options.
Could be ball bearings, a rock stuck in the rim, a loose lug nut... any number of things. Would need more information. When does the rattle occur? Is it constant? Loud? Is it a metallic sound, muffled?