I picked up the Grot Mega Tank at GamesDay 2010. It was available in limited numbers, but I was lucky enough to pick one up, before they sold out. I really do like this model alongside the Grot Tanks. The model is very ship like with battleship style turrets and a prow shaped bow. It is a very ramshackle vehicle and looks like (as it should) if the grots have just thrown it together from parts lying around the battlefield and stuff stolen from a Mek workshop.
Black was used for the tracks and to provide shadow, whilst the top of the model was done with a white undercoat.
The next stage will be the basecoat. I am unsure at this point if I will use a spray or a brush.