These very official-looking pictures of the 2013 Bentley Continental GT Speed convertible have popped up in the cybergarage, fuelling rumours that the real thing will debut at the Detroit auto show in a couple of weeks.

To judge by the pictures (no details have been released) it is what it is - a GT Speed coupé with the roof cut off, sporting a deep, quite aggressive front apron melding into neat side skirts, slightly lowered suspension, elliptical tailpipes and a set of very chav 21” alloys.

Expect it to be propelled by the same 460kW/800Nm six-litre W12 turbopetrol, eight-speed auto transmission and all-wheel drive as the tintop but, due to the inevitable extra weight of a convertible, performance will probably by slightly down on the coupé's 4.2-second sprint from 0-100 and 322km/h top speed - but not much.