Pink Tentacle has posted a great gallery of extreme Japanese custom vans, many of which look more like warp-speed capable Winnebagos than vans proper.
These pictures have made me consider tricking out a van myself. To be fair, I once considered it, back in high school: my friend Dong Diep and I envisioned converting a rusty van he had purchased for a couple hundred bucks into a mobile seduction lab, with hydraulics, lava lamps for headlights and a water bed in back. The true genius addition to our design was a drag chute that could be thrown out of the back of the vehicle if we happened to zoom by a beautiful girl at 90mph: in the style of the 1960's Batman TV show, this would allow us to turn the van around on a time, wasting no time in going back and bombarding her with our embarrassing high school "playah" patter.
Needless to say, this plan never went anywhere, but not due to lack of practicality: I revolted when I discovered that Dong wanted Bob Marley to be on constant subwoofer rotation.
Extreme Japanese custom vans [Pink Tentacle]