We’re big fans of the Corvette Z06, which with its 7.0-litre V8 churning out 506bhp and 470lb ft offers proper supercar performance to go with its supercar looks. But that’s clearly not enough for some people. North American tuning specialist Callaway has just announced its C16 Convertible, based on the Z06, but with bespoke body panels and even more power.The C16 Convertible – sister car to the C16 coupe, which is already on sale, will be unveiled at the New York motor show in April. Like the coupe, it gets engine modifications that increase power to 552bhp as standard, with the option of a 608bhp (616hp) kit, if you have a particular dislike for your rear tyres.With the standard six-speed automatic gearbox – operated by steering wheel-mounted paddles – even the standard C16 cabrio will hit an estimated 200mph, and the manual version will do 0-60mph in a claimed 3.5sec.Naturally the chassis gets tweaked to cope with the extra power as well, with special Eibach springs and dampers, and massive upgraded brakes. Wheels are 19-inch alloys up front and 20-inchers at the back.Along with specially tailored body panels, the C16 also gets a retrimmed leather and Alcantara interior.In the US, a fully loaded C16 Convertible will cost you $128,765, or about £66,500. However, expect taxes and shipping to make that nearer £100,000 if you order one through Callaway’s European dealer in Germany.