Here is quite a hard-hitting image to remind people to buckle up, even in the back seat. We should all know the benefits of seat belt usage by now, but some people still seem to think they might be immune in an accident, should they choose the rear seat rather than the front, for some reason. This powerful visual reminder might help to convince them they're wrong.
Taking 3D billboards to a new extreme, the slingshot seems to dwarf the billboard itself, effectively conveying the force that will propel you forward in a collision. The one thing the ad doesn't replicate, however, is the variety of surfaces you'll impact after launch. Seatbacks might not seem particularly harmful, but anything you strike will be painful as you fly into, over or around them at those velocities. We're not quite sure where this billboard is located or who was responsible for it, but we like it a lot. Buckle up. Even in the back seat.