How far in advance should I book a car?

For an ordinary weekday transfer, the day before is comfortable and a few hours is usually fine. The honest constraint is not the car, it is which chauffeur is free — booking earlier is how you get the one who already knows you.

Three cases genuinely need more notice. An event week, when a whole city is trying to move at the same hour and every operator in it is already committed. A large party or a specific vehicle class, because that is a particular car rather than any car. And anything before six in the morning, which needs a chauffeur whose night was planned around it.

Art Basel, the Grand Prix, a season weekend in Palm Beach: a week or more, and earlier still if the timing is tight at both ends. Outside those, this is not a service that punishes you for a short notice, and a concierge will tell you plainly if a time cannot be done well rather than accepting it and hoping.

Late notice is never a reason not to ask. If it can be done it will be, and if it cannot you will be told while you still have time to arrange something else.