For this render I used a photoshop texture map for the painted concrete ground and created two different renders with different outdoor lighting settings with to adjust shadow softness/hardness. I overlaid the renders in photoshop and used the transparency setting on one of the layers to achieve the desired combination. I added a little noise, a pixel of chromatic aberration and found some photoshop dirt/scratches textures to ever so slightly create surface imperfections on the old ipods.
I still don't think its quite there yet but I would value anyone else's input as to how to improve the photorealism further.
Many Thanks
Rob