Last March, at the Geneva Auto Show, Alfa Romeo displayed a concept of the 4C Spider –  the open-top version of its 4C sports car that would launch some time in 2015.

Although the production version is expected to make its debut in the upcoming Detroit Auto Show, judging by its US rear number plate, has already been snapped in the open by Autoblog.it as well Carscoops reader Luka C.

As expected, the final version is almost identical to the concept, apart from the twin exhausts that are now in the two ends of the rear bumper, just like the Coupe, instead of the middle, and an extra air intake just aft of the right rear wheel that provides extra cooling to the transmission. The good news, though, is that it retains the concept’s headlights which, for us at least, are prettier than the fixed-roof version’s.

The 4C Spider is built on the carbon fiber chassis used in the Coupe and is powered by the same turbocharged, 1.75-liter four-cylinder that’s good for 237hp (240PS) and 350Nm (258lb-ft) of torque. The all-aluminum unit sends its power to the rear wheels via a six-speed dual-clutch TCT gearbox.

We’ll have to wait for Alfa Romeo to reveal the official specs but we figure it will sport similar numbers to the Coupe’s 4.5 0-62 mph (0-100 km/h) acceleration and 160 mph (257 km/h) top speed. Just like the Coupe, the US-bound 4C Spider will, most likely, be heavier than its Euro counterpart due to the extra aluminum reinforcements needed to comply with federal crash regulations.

Thanks to Luka C. for the pic!

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