I would have a quick consultation with a solicitor. I expect they would tell you that you don?t need to know the driver of the van (or which van) if you have a witness to confirm that a company vehicle damaged your car (don?t treat it as a motor incident, but as criminal damage). I?d also make sure the CEO of Churches is involved - he may care more about the potential liability and negative PR than the fleet manager (who probably already knows who was driving - it may even have been him). Finally, remind Churches that failure to stop after a collision is a criminal offence, and it may be better to resolve this issue now rather than escalate it.