The castle that Robin wants to buy is Leeds Castle in Kent in the South of England. A castle has existed on the site since 1119, the first being a simple stone stronghold constructed by Robert de Crevecoeur which served as a military post in the time of Norman intrusions into England. In the 13th century it came into the hands of King Edward I, for whom it became a favourite residence; in the 16th century, Henry VIII used it as a dwelling for his first wife, Catherine of Aragon. The present castle dates mostly from the 19th century. It has been open to the public since 1976.
This episode was split into two parts part one and part two for syndication
The three-wheeled car that Higgins drives is a Reliant Robin. This is the model that, in 1973, replaced the Reliant Regal; a car that gained great comic acclaim on the British series Mr. Bean (1990) for the ease in which it could completely tip over in a turn.
The white helicopter seen at the beginning (G-BLEV) is a 1984 Eurocopter AS-355 c/n 5311. These are also known as the TwinStar or Twin Ecureuil (Squirrel) and are the twin engine version of the popular AS-350 AStar.
Besides the 1937 Bentley shown here appearing in a James Bond-universe film "Never Say Never Again, 1983, Julian Glover appeared as the main protagonist Kristatos in the James Bond-universe film "For Your Eyes Only",1981, adding another solid UK link.