Why didn't Toyota just build it on the Lexus RC or LC frame? They have everything that car would ever need to be built on those frames and they are close to 500 hp. It's next exactly a slouch. I don't get why they subbed most of this out to BMW when they had internal, coupe, RWD options already.
Well they partnered with the companies that helps makes them the cars, sharing tech and whatnot.
Toyota partnered with Mazda for tech. They got a Mazda2 based Yaris Sedan out of it (Toyota has a plethora of Yaris variants of their own outside of North America, they actually could have used themselves). Mazda doesn't sell a Mazda2 sedan in North America, except through Toyota.
Toyota partnered with Subaru to build the 86. Toyota funded the project (plus at the time they didn't really have their own sports car platform) and Subaru engineered it. Toyota also contributed D4S system. But then Toyota owns like 49% of Subaru so its really just resource leveraging on Toyota's part (since the 86/BRZ doesn't fit into Subaru's AWD ethos)
Toyota partnered with BMW for tech. Not sure what they actually contribute but it was said that this sports car was part of the collaboration. I guess being a Supra made the most sense since it was I6 based, and BMW always had an i6.
There's word of a MR2 revival and possibly the Celica returning.
I think the main thing with Toyota is that they didn't have any viable platforms for these sporting vehicles back when they were thought up. Only now are we seeing Toyota modular platforms for everything (hell only now we're seeing NEW Toyota everything)
Back then they only have their FWD passenger car platforms. Even Lexus didn't have anything special. The RC coupe was built on a hodgepodge Frankenstein platform consisting of 1/3 current GS, 1/3 current IS sedan, and 1/3 previous IS convertible. The LC is on their new RWD luxury car platform (also being used on the new LS)
Maybe now with their new platforms and all that, they would be able to build their own sports cars.