The Bishop of Botolph

In the novel Why Didn't They Ask Evans?, the Bishop of Botolph is mentioned by Inspector Williams.

His car is a bark blue Talbot saloon with the number GG 8282. A car with the same number plate as the bishop's was seen around the time of the death of Alan Carstairs. The bishop's car had however never left his residence that day, so the car that was seen had false number plates.