Company MD Peter Boutwood said the prototype is likely to use a T-bar roof arrangement with removable carbonfibre panels set around a fixed longitudinal strut.
Renderings of an M600 roadster have previously been released, but the test vehicle will be the first open-top version of the mid-engined, 650bhp supercar. Structural rigidity will not be affected, says Boutwood.
The company has also confirmed development of a new automatic transmission option, conceived with the Middle Eastern market in mind. The set-up will use steering wheel-mounted paddles to operate an automated version of the existing Graziano six-speed manual gearbox.
While the £229,800 M600 is now five years old, there are no plans for a facelift. “We won’t do an update just for the styling,” said Boutwood. “The engineering of the car is still where we want it to be.”
Boutwood also revealed that he would like to build a “more affordable” car in the mould of the smaller, 425bhp M400, which was manufactured in South Africa between 2004 and 2007 and priced at £62,000. However, Noble is now committed to UK manufacturing, so the margins on such a vehicle would be unjustifiably small, he said.