The cars
Mercedes-Benz S-Class
The executive saloon the others are measured against.
Unremarkable in the best sense: it draws no attention at a hotel door or a ministry gate, and it is the car most people travelling on business would choose for themselves.
Chauffeured by a driver who is briefed before the first pick-up, and arranged for exactly as long as you need it — a single journey, a day, or a retainer.