Painting "Rust" on a Trukk and Skorcha Buggy

So I was experimenting with "rust" painting techniques all weekend. I bought and put together a real GW Trukk instead of scratch building (shocking I know). I also rummaged around my old box of Ork bitz and found a buggy in need of a home. I used one of my several dozen Kinder Surprise Eggs and turned it into a Skorcha buggy (like the "turret?" :) ).