This one:
http://www.flickr.com/photos/52467480@N08/6454428569/in/photostream/
Interesting vehicle, I dont think the patch painting is random, think it's had one of the various 'disposal' brandings applied, possibly 'SUBEX2' which IIRC was for vehicles sidelined for inspection but not actually condemned, and was painted out if the wagon was found to be OK. Look at the wagon to its right also - at a glance at at more distance, you'd take it for 'overall' rust but there are several distinct shades in interesting disposition. Similarly the second wagon in Mike's shot is only moderately rusted on the sides, but heavy on the ends - modellers I think often apply rust flakes in a too evenly 'spaced out' pattern, possibly subconsciously.