A Nuremberg chauffeur service is private transport booked in advance at a fixed euro price and driven by a Mietwagen operator licensed by the Ordnungsamt der Stadt Nürnberg (Stab Verkehr, Bürgerdienste Mobilität) under the Personenbeförderungsgesetz, the federal Passenger Transport Act. It is not a taxi, it cannot be flagged down, and it never waits at a rank. The car, the chauffeur and the total are settled before pickup, whether the job is a Nuremberg Airport transfer, an hourly car service across a fair day or a black car to a meeting in Erlangen.
German law shapes how this works for you. Section 49(4) of the PBefG says a Mietwagen may only carry passengers on bookings received at the operator's business seat, and after each trip it must return to that base unless the next booking was already in hand, the rule known as the Rückkehrpflicht. In plain terms, a RYDES car in Nuremberg is always pre-booked, always at a price agreed beforehand, and the chauffeur at the kerb is there for you by name rather than for whoever reaches the door first. RYDES arranges the booking; the licensed chauffeur operator carries out the journey. That is also why a Nuremberg car service booking costs the same when the A73 is jammed: there is no meter to keep running.
One reservation covers the wider region. Fixed NUE to Altstadt and NUE to Messe Nürnberg runs, the commute to Erlangen and Herzogenaurach, evenings at the Christkindlesmarkt, and long runs such as Nuremberg to Regensburg or NUE to Munich Airport. Weighing it against the rank is covered on the Nuremberg taxi alternative page, and companies with travellers here every month use corporate travel in Nuremberg for central invoicing.