Ireland and overseas, which is provided by the Special Detective Unit (SDU), an elite wing of the Irish police force. Protection is increased if there is a known threat. The presidential limousine is a Mercedes-Benz S-Class LWB. The Presidential Limousine is dark navy blue and carries the presidential standard on the left front wing and the tricolour on the right front wing. When travelling the presidential limousine is always accompanied by support cars (normally BMW 5 Series, Audi A6 and Volvo S60 driven by trained drivers from the SDU) and several Garda motorcycle outriders from the Garda Traffic Corps which form a protective convoy around the car. The president-elect is usually escorted to and from the ceremony by the Presidential Motorcycle Escort ceremonial outriders. Until 1947 they were a cavalry mounted escort, wearing light blue hussar-style uniforms. However to save money the first Inter-Party Government replaced the Irish horses by Japanese motorbikes, which the then Minister for Defence believed would be "much more impressive." At the presidential inauguration in 1945, alongside the mounted escort on horseback, president-elect Seán T. O'Kelly rode in the old state landau of Queen Alexandra. The use of the state carriage was highly popular with crowds. However an accident with a later presidential carriage at the Royal Dublin Society Horse show led to the abolition of the carriage and its replacement by a Rolls-Royce Silver Wraith in 1947. The distinctive 1947 Rolls-Royce is still used to bring the president to and from the inauguration today. The Presidential State Car is a 1947 Rolls-Royce Silver Wraith landaulette, which is used only for ceremonial occasions. The president also has the full use of all Irish Air Corps aircraft at his/her disposal if so needed, including helicopters and private jets. History The office of president was established in 1937, in part as a replacement for the office of governor-general that existed during the 1922–37 Irish Free State. The seven-year term of office of the president was inspired by that of the presidents of Weimar Germany. At the time the office was established critics warned that the post might lead to the emergence of a dictatorship. However, these fears were not borne out as successive presidents played a limited, largely apolitical role in national affairs. Head of state from 1937 to 1949 During the period of 1937 to 1949 it was unclear whether the Irish head of state was actually