The first GM intercity coaches were built by a subdivision of GM called yellow coach. The first model, the 719 began production in the mid 30's and was later upgraded to the 743. In November 1939 the first intercity coach to be built under the GM name began production. It was the PG-2501, the P stood for parlor versus T for GM's transit buses. Through about the next 41 years GM built about 23 000 parlor coaches including the PG-2501, but not including the 719 and 743. There were 45 different models of parlor coaches that GM and Yellow Coach built throughout the years. However several models would be a very similar bus with just some minor differences.

The P8M-4905A is a good example of how several models would have many similarities. The bus actually started out as the PD-4903 in April of 1968. This was the first 40 foot coach from GM that was available to operators other than Greyhound. 401 PD-4903's were sold in 1968 and 1969. In February 1970 the PD-4905 was introduced and sold 331 units in 1970 and 1971. The P8M-4905A was introduced in 1972 and offered an optional retractable third axle (tag axle). This model sold 2027 units from 1972 through to 1978 and the coach featured on this page is from this series. The very last GM parlor coaches sold were the H8H-649 which sold only 233 units and was a continuation of the P8M-4905A. Production ended in July 1980. At the time Motor Coach Industries and Eagle Manufacturing respectively subsidies of Greyhound and Trailways were becoming stronger players in the market thus General Motors decided to end production of it's intercity coaches.