Aston Martin is keeping up its 2009 new-model offensive with the V12 Vantage, the hottest version of its two-seat coupe.Revealed just days after the Rapide four-door, the V12 Vantage is the second of four major reveals from Aston this year. Also coming is the DBS convertible, which will share stand space at Geneva with the V12 Vantage and a concept for a new Lagonda, the dormant brand that Aston plans to bring back to life as a super-luxury Rolls-Royce/Maybach challenger.Amid this flurry of new-model launches, the bad news for U.S. enthusiasts is that the V12 Vantage won't be sold in this market. Aston cites legal issues for the engine and crash protection, particularly the optional bucket seats without side airbags.U.S. buyers might feel they've been jilted, particularly since the V12 Vantage borrows one of the oldest tricks known to West Coast tuners--shoehorn the biggest and most powerful engine into the smallest and sexiest two-seat British sports car.Back in the '60s, the practice was to throw out the weak British four or six and replace it with a thumping V8. These days, a V8 isn't enough, so the hot Vantage gets a lusty 6.0-liter V12 from the DBS transplanted under the hood to create a super-quick and compact range-topper for the Vantage lineup.'This is the ultimate performance interpretation of the Vantage range, combining our most agile model with our most powerful engine,' says Uli Bez, Aston's CEO.With 510 hp on tap, the V12 Vantage matches the Ferrari F430 Scuderia. And with 3,704 pounds to haul around, the V12 Vantage is certainly quick on paper--Aston quotes a 0-to-60-mph time of 4.1seconds and a top speed of 190 mph, although that's not quite quick enough to match the Ferrari.