More or less just a repaint. Although, I did sculpt some blast marks into his armor. Tried to make him as grimy and battle-worn as possible.
I painted all the rusting, the silver hubcaps, the grey side strip, and the red tail lights. All blast marks were sculpted with an exacto knife and then painted. Also gave him some mud splatter behind the wheels.
Vehicle mode front
Again, more scaring, rust, and mud splatter. Painted the window wipers black.
Gave the entire figure a wash of brown to better outline all the panels and other details. Also painted his stomach grating silver.
Robot mode right
Robot mode back
Robot mode left
You can see more details at my blog...http://hougesandwich.blogspot.com/2011/10/custom-sergeant-kup.html
Painted Kup before blast marks were addedhttp://hougesandwich.blogspot.com/2012/01/updated-kup.html
Kup with sculpted battle scars and decals