When Banstead gives Steed a drink, he remarks that it's non-alcoholic so it is safe to drive. This is probably a reference to the fact that, in the UK, the Road Safety Act 1967, passed in the same year that this episode was first broadcast, first introduced a legally enforceable blood alcohol level.
The racing circuit in Benstead's simulation is Brands Hatch.
At the end of this episode, Mr. Steed gives Mrs.Peel a rare, loving kiss behind her cheek. Emma smiles approvingly.