Fiat, like MINI before it, thinks it's on to a good thing with its retro-styled small car, the 500.

And like MINI, the Italian automaker thinks the best way of expanding on the car's popularity is to apply the badge to a whole range of vehicles--the latest being a four-door version of the currently two-door minicar.

Auto Express carries computer-generated images of what the new model could look like when it appears in 2015.

In Europe, the four-door 500 will replace the existing Fiat Punto subcompact--once one of Fiat's most popular models, but lately forgotten in the face of stiff competition and Fiat's own higher-profile 500 models.

As such, the new four-door 500 will ride on a modified version of the Punto platform, rather than the underpinnings of the existing 500. Fiat already uses the Punto as a basis for its largest 500 family members, the 500L and 500 MPW.

The car will compete with rivals such as the Ford Fiesta, though like the 500 before it, the MINI and cars like the Citroen DS3 sold in Europe, Fiat is likely to play heavily on the car's style and premium features, rather than the more utilitarian nature of many rivals.

MORE: 2014 Fiat 500L: Gas Mileage Test Of New Tall Wagon

Fiat Group design boss Lorenzo Ramaciotti told Auto Express that Fiat's future branding will follow two lines--the more emotional, exclusive 500 range (soon bolstered by a 500X crossover, too) and a more practical, easy-to-use range kicking off with the Panda--a four-door small car on the 500's platform.

While unconfirmed, it's likely the model would also be sold in the U.S.

Fiat kicked off its American revival with the 500 in 2010, and has since introduced the 500C convertible, the sporty Abarth, the highly-rated 500E electric car and the larger 500L. A Fiesta rival could slot neatly into this range and boost choice for customers in the subcompact market.

Engines are expected to be taken from the existing 500 range.

For the U.S, that would mean a small range of four-cylinder gasoline units, though in Europe the firm's four-cylinder diesel and twin-cylinder TwinAir units would also feature.

Would introducing a four-door 500 be a good move in the U.S? Leave your thoughts in the comments section below.

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