A Toyota spokesperson told Reuters at the 2015 Frankfurt motor show: "By the end of the year we will approve whether or not we will make it. The whole study before that, on what kind of platform, on what kind of architecture, that's been progressing quite well. We haven't yet decided to give the green light to the project, but it's coming up."
BMW and Toyota are currently working together on a number of projects including hydrogen fuel cell technology, lightweight components, and a platform for a new sports car. Additionally some Toyota models in Europe, including the mid-size Avensis, use BMW turbo-diesel engines.
If the sports car project gets the go-ahead, it's expected that the new architecture will be used by BMW for a Z4 replacement, while Toyota would produce a car that would be a successor to the Supra.
The current Z4 debuted at the beginning of 2009 and has soldiered on with some minor changes since then. Although it had a cult following, the Toyota Supra was discontinued in 2002 and was not replaced. In 2014, Toyota unveiled the FT-1 concept car, which provides clues as to what a future larger-than-86 coupe might look like.
Since the two automakers began collaborating on fuel cell and sports cars, rumours have circulated that the partnership would expand to include other projects, including possibly a smaller Mini.
Friedrich Eichiner, BMW's chief financial officer, told the newswire that the two companies were in talks about extending their collaboration, but didn't elaborate any further. An earlier report indicated that BMW will launch a fuel cell vehicle in 2020.
Johan van Zyl, head of Toyota Europe, told Reuters that the current projects being undertaken by the two automakers are on schedule, but refused to comment further.