When i set up my current van, i assumed that the main danger from water sloshing about would have been from side to side, so i mounted the tank with the baffle in line (this, despite my previous van, which had its system fitted by a company, having the baffles across the van!). Immediately after i started using it, i was freaked out by the fore-aft movement of the water whenever i came to a stop or pulled away!. I don't know if it was just that it made me drive smoother, or i just got used to it, but after a few months i stopped noticing it!.