Much has been said about Toyota and BMW's relationship during their time developing the Supra and Z4 Roadster, respectively. Most people continue to lament the German automakers heavy involvement in the Japanese sports coup's development, though the truth, as is often the case, lies somewhere between what people think and what actually transpired. It's true that BMW was heavily involved in certain aspects of the Supra's development, including supplying a handful of important parts, including the one you'll find when you pop open the Supras hood. Lift it up and youll see the sports cars beating heart: a 3.0-liter, turbocharged, inline-six engine that looks like it was crammed in that space with very little room for anything else. Its easy to look at this setup and see Bimmers fingerprints all over the Supras development, but the Supra is still more than just a Z4 Roadster wearing a different body and sporting a Toyota badge on it.