From the
Brookland Museum web site: General guidance on admission policy for classic cars via the Campbell Gate Entrance:
Subject to events taking place, the following are generally admitted through the Campbell Gate
Any vehicle more than 30 years old (or an example of a model that went into production before 1987). This means a prefix of D for those cars without personalised number plates).
Significant, collectible more recent cars are also admitted, such as Morgan, Ferrari, Maserati, Lamborghini, Rolls Royce, Bentley or Aston Martin (this list is not exhaustive).