GENEVA — Teased to within an inch of its life on the Web, the Aston Martin One-77 finally made its first official public appearance at the 2009 Geneva Auto Show, providing a rolling showcase of supercar technology.Said to be inspired by DTM racing, the One-77 is described immodestly by Aston as the company's 'definitive sports car.' According to Chief Executive Ulrich Bez, it is 'the ultimate expression of Aston Martin.'Still months away from production, the One-77 is about to commence durability and performance testing. Aston engineers are particularly keen to see how the new 12-cylinder engine, jointly developed with Cosworth, unwinds.The normally aspirated 7.3-liter V12 is designed to produce a whopping 700-plus horsepower, feeding the rear wheels through a new six-speed 'robotized' sequential manual gearbox with paddle shifters. The performance targets are 0-60-mph acceleration in 3.5 seconds or less, and a top speed in excess of 200 mph.Underneath the stunning skin is a rigid carbon fiber tub, developed in cooperation with composite specialist Multimatic. The One-77 features double wishbones and adjustable shocks as well as carbon-ceramic brakes and Pirelli P Zero Corsa tires (255/35ZR20 front, 335/30ZR20 rear).One small perk that lucky owners will enjoy as part of the projected seven-figure price tag: As part of the delivery process, Aston engineers will set up the car's suspension to the owner's individual taste.Inside Line says: This ultracar wannabe boasts impressive specs on paper — but has a long way to go to catch the Bugatti Veyron. — Paul Lienert, Correspondent