Harry Bates, who won the 2019 title, and younger brother Lewis Bates, who finished runner-up, will each compete in one in under the Toyota Gazoo Racing Australia banner.
That programme is run by long-time partner Neal Bates Motorsport, although the latest project represents the first in which Toyota Australia has been actively involved.
The AP4 (Asia-Pacific 4WD) specification is similar to that which applies in WRC2, the second tier of the World Rally Championship, which is the domain of Rally2 and R5 vehicles.
“This really has been a collaborative effort to help bring these cars to life and we are looking forward to their competition debut,” said Neal Bates.
“The design not only gives us a great looking car, but fine-tuning the shape of the fenders and bumpers and other body parts using Toyota's advanced technologies has helped give us an aerodynamic edge.
“We also worked with Toyota Gazoo Racing Europe on the 1.6-litre three-cylinder turbo engines, which have been slightly modified from the standard GR Yaris unit to comply with the AP4 regulations, while still delivering extremely quick response and optimum driveability for rallying.”
The engine is based off the production version, with standard block, head, and inlet manifold, but bespoke exhaust manifold and 1.5 bar maximum boost turbocharger.
The gearbox is a six-speed sequential Sadev unit, while a fiberglass bonnet and hatch, lightweight 3D-printed mirrors and bonnet vents, and Perspex windows are married to the production standard aluminium doors and carbon-fibre roof.
With a 1230kg category minimum weight, the GR Yaris AP4 will carry ballast to bring it up to regulations.
“People often think that a rally car is just a modified road car, but it really is a Supercar for the gravel, the build process is identical to that of a Supercar,” explained Neal Bates.
“In a rally car you have to use the standard shell but obviously you modify that quite a bit and a lot of it is about reducing weight.”
Toyota Australia Chief Marketing Officer John Pappas said, “We have had a very successful relationship with Neal Bates Motorsport and the team ever since Neal first raced for Toyota Team Australia at Bathurst in 1989 and we're very excited to be unveiling the GR Yaris AP4 – a car designed and built in collaboration with NBM.
“As a driver Neal has had a very successful career over the past 30 years and now, as TGRA team principal leading the build on these two fantastic GR Yaris AP4 rally cars, we believe he can look forward to more successes.
“We would like to wish the TGRA team all the best for the 2021 ARC season and given the pedigree of the cars, we hope to see Harry and Lewis regularly topping the podium.”
The 2021 ARC season starts which the Netier National Capital Rally, which has been rescheduled for April 9-11 due to heavy rain in the Australian Capital Territory.