Proton is set to return to the World Rally Championship in 2018 with a brand new Iriz R5 built by British firm MEM.
The Iriz is under construction at MEM's Derbyshire factory and is scheduled to break cover at next month's Goodwood Festival of Speed.
Chris Mellors' MEM firm was also behind the last Proton rallying project with the Satria, which was a podium-finisher in the Intercontinental Rally Challenge, won in the WRC's old Super 2000 class and was a title-winner in the Asia-Pacific series.
"We started looking at this with Proton last year and straight away we were excited by what we saw with the road car," said Mellors. "The size and shape of the Iriz is perfect for rallying.
"Everything is in the right place: the overall length of the car is shorter than the Satria, but the wheelbase is longer; the strut tops are in just the right place; there's lots of frontal area which is great for cooling.
"We've got a great base car and into that we've put all the right ingredients. The engine's fabulous: really powerful and light. It's the [Mitsubishi Lancer] Evo X engine taken down to 1600cc – a process which will help make it even stronger than it is.
"As well as a great engine, we've got Xtrac transmission, Reiger dampers, Brembo brakes and Cosworth electronics.
"The ingredients in this car are absolutely all there – we've put everything into it and with those component parts we're going to have one heck of an R5 car."
MEM's intention is to enter both WRC2 and the APRC with the new car.
The previous Proton programme ended four years ago when production of the Satria Neo base car ceased.
"Proton never lost its interest and desire to compete in rallying," said Mellors. "It was just the practical point that there was no car.
"Proton is really excited by what we've got here. We've still got a lot of work to do, we've got a lot of testing and development to do – and the debut at the Festival of Speed is pretty ambitious, but we're well on with the job."
The Iriz R5, which will be available in both left and right-hand drive, is set for a January 1 homologation.