When the final list for the Car of the Century competition was announced in November 1999, only one company had three finalists: Automobiles Citro?n. All three models were developed during the era when the company was owned by the Soci?t? Michelin (Michelin Tire Company). This work provides the first in-depth examination of the Citro?n-Michelin era, focusing on the interrelationship between these firms in the development of the revolutionary Michelin X radial tire and its impact on Citro?n's avant-garde automobiles. From its origins in 1919 under the watchful eye of Andr? Citro?n, a history of the automaker's early years is provided. Next, the author takes a detailed look at the cars of the golden age of Citro?n: the Traction Avant, the 2CV, the DS/ID, the GS/GSA, the CX, and the Citro?n-Maserati SM. The innovations, the unique designs, and the new standards of technical excellence that these cars offered are all fully covered, heavily illustrated with rare photographs.