Photo Archive In 1943 Yellow Truck & Coach Manufacturing Co. became a division of General Motors and was renamed GM Truck & Coach Division. The first GM badged buses were built when the War Production Board (WPB) authorized production of 1,340 transit buses. The first highway GMs were built in 1944 when 700 parlor cars were allowed by the WPB. Between August 1923 and May 1987 approximately 128,000 buses were built by Yellow/GM with another 12,000 built in Canada by GM Diesel, Ltd. All the buses shown in this book were built in Pontiac, Michigan including those for delivery in Canada.