The Metropolitan was designed in the USA by William J. Flajole, for Nash Motor Division of Nash-Kelvinator Corporation. Fisher & Ludlow, Ltd., built the body and the mechanical outfitting was done by Austin Motor Company, Ltd. Both companies were in Birmingham, England.

Production of the Metropolitan began in October 1953. The original cars were badged "NKI Custom". (NKI - Nash Kelvinator International) 

First cars arrived in North America in December '53.

On January 22, 1954, the name was officially changed to "Metropolitan".

Official launch date was March 1954. All "NKI Custom" nameplates were supposed to have been removed and the "Metropolitan" nameplates installed, but some did make it out to the public before the changeover. These were to be changed when they came in for service. (The only known example of the original "NKI Custom" script still being on a car is one in a museum in California, although this could have been re-installed at a later date.)

There were two models, 541, Convertible, and 542, Hardtop Convertible. They were equipped with a 1200cc Austin, A40, engine.

On May 1, 1954, Nash-Kelvinator and Hudson Motor Car Company merged to form American Motors Corporation. By mid 1954, the Metropolitan was being marketed as a "Hudson Metropolitan" as well as a "Nash Metropolitan". The models were identical, with the only difference being the grill emblem and horn button. The "Hudson Metropolitan" used the "bull's eye" horn button that would later be used on all Metropolitans. The "Nash Metropolitan" still used the "Nash" hubcaps for a short while, but soon changed to the "M" hubcap used by the "Hudson Metropolitan", and all later Metropolitans. 

As there were no model changes to differentiate the year, all Metropolitans sold after November 26, 1954 were registered as 1955 models. All Metropolitans sold after December 15, 1955 were registered as 1956 models.

In January 1956, the engine was changed to a 1500cc Austin A50. The grill was changed, and so was the front hood. Chrome molding was added to the side, and the "two-tone" Metropolitan was born. The model names were changed to the 561, Convertible, and the 562, Hardtop Convertible. The first of these were in the showrooms by mid 1956. As there were still 541's and 542's in the dealerships, dealers were told to refer to the "new" Metropolitan as a 1500, but apparently, this was not an official model name, even though it did appear in advertisements. All Metropolitans sold after October 25, 1956 were registered as 1957 models.

As of the 1957 model year, the names of "Nash Metropolitan" and "Hudson Metropolitan" were dropped, and the name "Metropolitan" became the marque. (The names Nash and Hudson were also dropped from the Rambler line. The only car to bare the name "Nash" in 1957 was the Ambassador, and the sole car with the "Hudson" name was the Hornet. These names were dropped in 1958.)

All Metropolitans sold after October 22, 1957 were registered as 1958 models. The Metropolitan continued with minor changes/improvements through 1959, 1960, with production ending on April 19, 1961. The last Metropolitan built for the North American market was E-95981. As there were over a year's supply of Metropolitans in stock, both in England and North America, they continued to be sold with a 1962 model year commencing on October 6, 1961. The announced end of the Metropolitan came on March 23, 1962. There were less than 1,000 cars in stock at that time. The 1959, 1960, and 1961 model years started on October 8, 1958, October 14, 1959, October 12, 1960. 

In December 1956, The Austin Motor Company aquired the right to sell the Metropolitan outside of North America. Austin started marketing the car in April 1957. This car is often referred to as an "Austin Metropolitan", but in fact it never bore the name "Austin" except as the manufacturer. Like the North American car, it was simply a "Metropolitan". There were both left and right hand drive Metropolitans sold in both markets. 

There were approximately 95,000 Metropolitans built for sale by Nash/Hudson/AMC. The first serial number was 1001, and the highest one is E-95986. The interesting thing is that the last 5 serial numbers were in reverse order, and they were not the last Metropolitans built. The highest number, E-95986, was built in September 1960, while the last Metropolitan for the North American market was E-95981 and it was built on April 19, 1961. These last 5 serial numbers were all right hand drives.

Approximately 9,400 Metropolitans were built for sale by Austin. The serial numbers of the Metropolitans sold by Austin were not in sequence, but these cars were assigned Austin serial numbers on an apparently random basis. The last Metropolitan built for the domestic market in the UK was serial number 150301HS8. It was also built in April 1961.

(The above information was gathered from various sources, including “The Metropolitan Story” by Patrick R. Foster, and from information supplied by Chris Custin and David Austin. Chris Custin is “Team Leader – Metropolitan History” and David Austin is “Past to Present History”, both with MOCNA.)