Their web site is incredibly garish [1] but we really liked these vans from MOOVI in Spain – each van is equipped with two LED illuminated Advertising light boxes on both sides, and a video projection screen on the rear of the van.
[2]
The Lenticular technology [3] is quite limiting of course but there are plenty of effects, like zoom, flip, 3D, motion and morph to choose from to make enough of an impact to matter.