A convertible version of the ultra high-performance Mercedes-Benz SLS AMG goes on sale late in 2012. The SLS AMG Roadster joins the coupe version launched May 2010 as a 2011 model. The price of the roadster should be just under $200,000, including a big destination charge to cover careful handling. The coupe retails for $185,750. The Roadster version of the Mercedes-Benz SLS AMG gives up the signature gull-wing doors of the Coupe but gains less than 90 pounds, leaving performance effectively unchanged. It\'s still very quick at 197 mph and able to enter any drifting contest with its electronic safety nets switched off. With them enabled, it\'s a consummate Grand Touring machine. A multi-layer folding soft-top in black, sand or red is used to keep the center of gravity low and not change the front/rear balance, two key aspects of high-performance cars. The top may be opened or closed at speeds to 30 mph and the process takes only 11 seconds; it uses a glass rear window and takes away less than 2 percent of the cargo area. A wind deflector may be fitted between the roll-bars and the Airscarf system that vents warm air to occupant\'s neck areas is standard. Conventional doors replace the gull-wings, but eight airbags remain. The SLS AMG Roadster uses SLS AMG Coupe components underneath, including an aluminum space-frame chassis, free-revving 563-hp hand-assembled 6.2-liter V8 engine, rear-mounted seven-speed multi-clutch transmission and limited-slip differential, compound brake rotors and 19-inch front and 20-inch rear wheels. The fully independent suspension can be optioned with adaptive damping to keep the firm handling but allow a softer ride over long distances. One sits low in the SLS and visibility with the top up is less than ideal. Some mitigation comes in the form of now-standard blind-spot monitor system, and the rear camera aids backing. Inside, the SLS sport seats are trimmed in leather with trim touches available in suede, carbon fiber and piano black lacquer finishes. All the requisite features and amenities are covered and any Mercedes driver will find all the controls familiar; among the options is a one-kilowatt Bang & Olufsen sound system at 6.4 cents/watt. The Roadster will offer the broad option detail of the Coupe, including various forged alloy wheels, genuine carbon fiber engine covers and other trim, and a new AMG Performance Media package that\'s more performance instrumentation than what media suggest. At least two of the options, Alubeam silver liquid metal paint and carbon ceramic brakes, are more than $12,000 each. Super-car prices add up quickly and the SLS Roadster is not immune. The SLS AMG Roadster is the first convertible designed from the ground up by Mercedes\'s AMG division and makes a fitting partner to the coupe. You may miss the gull-wing door show but the Roadster sounds even better. With an expected 22 miles per gallon, the SLS could get slapped with a federal Gas Guzzler Tax.