Nowhereelse.fr shares [Google translation] a pair of photos of what may be the rear shell of Apple's rumored lower-cost plastic iPhone. While the site acknowledges that the part could simply be a Chinese clone of an iPhone 5 rear shell, certain features such as a round rear microphone hole and rounded rear edges are consistent with previous claims for the lower-cost iPhone, including leaked design drawings from a case maker.
Update 10:03 PM: Nowhereelse.fr has spotted two more photos [Google translation] showing the same part also in yellow and red.
Article Link: Possible Photos of Plastic Rear Shell from Apple's Lower-Cost iPhone [Updated]