https://www.topgear.com/car-reviews/...hBM4wY/driving
You can thank Toyota for the existence of the Z4. Toyota wanted a new Supra but didn’t have a platform. BMW saw the roadster market softening and wasn’t sure if it could sell enough to justify replacing the Z4. But sharing could satisfy the spreadsheet-jockeys. BMW of course is one of the staunchest global holdouts for straight-six engines and rear drive, two articles of faith for a Supra.
So the Supra gets most of the Z4’s basic engineering, which is BMW stuff. Engine, suspension and basic platform parts, and electronics too, come from BMW’s current set that’s used on every longitudinal car they’ve launched since the 7-er of 2017. The Supra is tuned and set-up differently from the Z4. Both the cars are built at a BMW-overseen line in the Magna plant in Austria.
So if it matters to you that a car has ‘brand purity’, you’ll be wanting the Z4. If you want a roadster, that’ll also be the Z4. The Supra, a coupe, plays to a different, JDM-infused vibe. So despite the common rootstock, these cars legitimately appeal to different audiences.