Looks like it could be a good show with a nice setting. Too far for me to ever be @rsed attending, but good luck with it. The advertising seems covered off, but I would suggest that your mate e-mails the guys who do the Leeds VW festival (Contact us page here --> http://www.vwfestival.co.uk/contact-us.php) as they have only been going a few years and admit themselves they made a few mistakes in the first couple of years. It might be worth asking their advice on what their errors were and what they did to combat them and any general advice when trying to start a new show.
