A few weeks after the Vantage , it’s now the all-new Aston Martin Vanquish ’s turn to get the convertible treatment. Hailed as the world’s fastest and most powerful front-engined cabriolet, the Vanquish Volante uses the same twin-turbocharged 5.2-litre V12 as the coupe, producing 824 hp and 738 lb-ft of …