This is that famous scene where Clarkson (or in this case Rainbow Dash) takes the corner too sharp and too fast, resulting in water flooding into the back and the Hilux going under with Hammond (or in this case Applejack) breaking down in hysterics due to the fact that they're sinking in a Pickup truck! xD
Interestingly enough, the water effects I've resorted to brushwork, which I painted onto the original before drawing the Hilux and the two girls on top. The last time I attempted this ripple effect was with my railway drawing 'The Lonely Crossing'. Basically finished painting at about 1am, then let it dry overnight with the radiator on to help, then started drawing the characters on top. :)