The British Touring Car Championship's NGTC prototype car will be built around the Toyota Avensis.
Series organiser TOCA, which will fully introduce the new low-cost NGTC technical regulations in 2011, said that the Japanese manufacturer would supply a donor car and a new bodyshell to the programme.
BTCC series director Alan Gow said: "We would like to thank Toyota for its generous and highly valued contribution to this project.
"The Avensis is an ideal platform for the new car; it's fully suited to the NGTC ethos and, just like our new BTCC regulations, is proudly built in Britain."
GPR Motorsport, which is responsible for the design and construction of the prototype machine, will put it through a test programme later this year with two-time champion James Thompson acting as development driver.
Thompson will then drive the car in the free practice sessions at the final BTCC event of the year at Brands Hatch in October.