Gordon Murray Automotive will expand its lineup of supercars with a new convertible. GMA is teasing the T.33 Spider ahead of its April 4 debut, showing off an early profile sketch of the new car that might feature a few new design tweaks that differentiate it from the coupe.

We have no details about the car at this time, as GMA said it would reveal the full technical details next week. However, we know it will have a V12 engine powering it. The T.33 coupe features a Cosworth-sourced naturally aspirated 3.9-litre V12, which GMA also uses to power the T.50. The engine makes 607 bhp and 333 pound-feet of torque in the T.33, which should be the engine’s output in the spider. It weighs just 178 kilograms (392 pounds).

The V12 in the spider should be available with either a six-speed manual or a six-speed paddle-shift transmission like the coupe. What might take a hit is the T.33’s superb power-to-weight ratio, which is better than the McLaren F1 in the coupe. The weight from the new hardware might add a few kilos.

While the T.33 Spider is a supercar with svelte looks and a potent engine behind the cabin, it should feature the same creature comforts as the regular T.33. We expect the convertible to come with Apple CarPlay and Android Auto. The teaser sketch also alludes to minor styling tweaks coming to the front and rear fascias, which look unique from the coupe. However, this is an early look at the car.

GMA says it has always intended to build a T.33 Spider. “In fact, I sketched the Spider before the coupe to ensure the proportions worked,” Gordon Murray said, adding that the T.33 Spider “would deliver a truly involving driving experience that’s quite unlike anything else.”

The T.33 starts at £1.37 million.