I knew (or at least occasionally chatted on IRC with) Pete Cooper when this was just an idea he had, over a year ago now, and to be honest I didn't think it would happen, but here we are. He went from idea to script to getting people together and getting started on props and concept art rather quickly. The first I remember hearing about the Warthog build being underway was last winter so it definitely took some time. He has an estimated budget of 30,000 British pounds for the whole project and says it could wind up being anywhere from 20,000 to 50,000. The Warthog is completely drivable, last I checked it was street legal in Britain, and it's only a few cm shorter and even less of a difference thinner than the in-game model (there's another Halo fan in Canada unconnected with this who does his best to get accurate measurements of everything in the Haloverse, and the dimensions of some things [I think including the Warthog] have been released by Bungie). He was going to make it authentic-- i.e., metal and fiberglass construction-- but budget constraints meant he had to have some more prototype-ish parts-- with the paint you can't tell though.
He wanted to get into directing and he wanted (like many of us) to see a good Halo movie get made so he combined them-- not to imply that's easy, or that he's especially devoted to this. Anyway here's a recent interview. [http://blog.willeth.com/2009/10/commanding-operation-chastity/]
