The car is booked for the day, not for a route. There is no printed schedule to keep to — you decide the order of stops, how long each one gets, and whether the plan from the morning still holds by lunchtime. Waiting at every stop is built into the price rather than charged as extra time. Entry tickets, guided tours, and meals stay yours to book; the chauffeur car, waiting time, and a fixed price agreed before you travel are what's included.
Day-length trips run further from Dublin than most people expect. Wicklow and Glendalough make an easy first day out of the city; the Boyne Valley suits a day built around Newgrange; Kilkenny works well as a city day. A longer push out to the Cliffs of Moher and the Burren is possible in a single day when the timing allows it — otherwise it sits more comfortably as the start of an overnight trip.