Back in 2013, BMW and Toyota signed an agreement that was supposed to bring only good things for both parties: a new supercar, improved hybrid-technologies and better cars. Well, the bad news is that this agreement will not affect the next-generation Supra, as it will remain an in-house-developed sports car. What Toyota will do however will be to help BMW develop the next-generation Z4. The consensus believes that BMW will design and build the body of the next Z4. using lots of carbon-fiber and aluminum, while Toyota will offer its next-generation plug-in hybrid technology to the sports car.
Source: Top Speed