Megatron's hips have been modded to give him more height, spikes added to the grille and roof of the cab, and extra tires to the outside of the foot. Hoses and wires were then added in different sections and don't interfere with transformation.
Megatron's cloak-tarp was tailored from an all cotton linen weave bought at Jo Ann's crafts and tie down straps were added after giving it a good weathering with different shades and splatters. A dip into water allowed it to hang on his robot mode and then when dry I used a mixture of water and clear sealant to get it to stay that way. The weathering the entire vehicle/robot modes were hand painted and given airbrushed, splatter effect, and line-detail rust along with various metallics before a sealer coat was added. Megatron's shotgun was made from a Gears of War gnasher with extra parts, a new handle, and hoses added.
"Igor", Meg's hunchback-head-minion was created from a RotF Long Haul head with fodder parts, Neo-shifter mini robot legs, and various hoses/cables. He's poseable and even has a tongue! Whew, this was one involved custom!
Tons more pics here!----> Dark of the Moon Megatron