 The first used were Buick and Cadillac motor cars, and Buick in the United States issued an advertisement in the "Saturday Evening Post" in 1927 with the legend "Buick carries the Desert Mail".Cadillacs proved very reliable, even in the extreme heat, due to their large radiators and excellent cooling systems.Gerald Nairn said "The Cadillac's ability to take punishment was just amazing" and by the time the firm dispensed with them they had done 200,000 miles each, at least 150-160,000 of which had been on the Damascus to Baghdad run.