I think P4, the timeline is because some of us remember the 1999 launch of the concept, the 2001 announcement of the production version and the prototypes having high-speed stability problems, with one destroyed in a crash and another spun out during a press demonstration. On top of the much documented cooling issues, VW sent the Veyron back to the drawing board for major revisions.
The purpose of prototypes is to test the cars AND to give to the marketing department. So none were "stolen" from the development team. Not sure where you got that snippet from but the intended 2003 production cars were dogs