SORRY smart ... you just cannot be serious. Beach buggies are so yesterday.

This door-less, roof-less and rear window-less concept car is unlikely to ever make it into production.

But put in a couple of doors, a proper roof and a back window and the smart fourjoy provides confirmation that the micro-car maker is set to go back into a market it abandoned when it ceased production of the smart forfour a few years ago.

For it comes with four seats and the company says it is the forerunner of a new smart generation.

According to Dr Annette Winkler, head of smart: "The smart fourjoy is a study that successfully translates the unique design and the urban driving fun of the smart fortwo to an extremely compact four-seater. The exterior proportions reveal a lot about the appearance of our four-seater production smart which will be launched at the end of 2014 and will also enable families to travel together in a smart."

The concept car, which will be revealed in the metal at the Frankfurt motor show next week, has an electric drive based on the current smart fortwo electric drive with the 55 kW magneto-electric motor housed at the rear.