I would be grateful for advice on a charity event. We hold a one day car show in our village and all proceeds after expenses go to charity. We attract a lot of visitors and, after the roads were blocked completely one year we now hire a field off a local farmer for visitor cars. We have stewards and post large signs saying cars are parked at owners risk. Taking into account that cars will be insured – do we need to put this on our event insurance, already costing us a lot of money?