Here is the VAB as purchased, 10p in the local charity shop - was probably part of a cheap bulk "army vehicle" set when originally sold. I've always liked the VAB body shape, I prefer the 6-wheeled version but this one will do for now. Reminds me of the old Action Force troop carrier.
A wash of heavily diluted matt black provided shading, then I drybrushed the whole thing with Humbrol 93 desert yellow for a dusty finish. Headlights are painted silver, other bits such as the horn and shovel head are GW chainmail. Tyres were painted Humbrol 29 dark earth, then drybrushed with matt black. I hope that's given the effect of road dust/dirt stuck in the treads.
A worthwhile experiment - although the initial paint job looked very harsh, the shading and drybrushing have blended it together well. Looking back, I shouldn't have left the camera set on the colour-boosting "Fuji Velvia" setting - the colours aren't this vibrant in real life, so it looks rather more subtle than it does here!