There has been a lot of media attention about runaway Toyota vehicles lately.

Below is one persons "how to stop a Prius" video.  These techniques would work on a vanagon as well.

Disclaimer; the video is extremely offensive to many, especially if you don't like hearing the "F" word repeatedly....but his point about driver training and understanding how vehicles work is spot on.

http://www.youtube.com/watch?v=lZ4PtafRB9c&feature=player_embedded