Today's BMW Z4 is quite a bit different from the Z3, which launched back in 1995. That car was more comparable in size, weight, and handling to the Mazda MX-5. But its Z4 successor changed that. BMW essentially turned its roadster into more of a grand tourer, culminating with the Z4 you can buy now. Problem is, global demand for roadsters and coupes has gone down in recent years, and the business case for a successor isn't the easiest to make.

Still, BMW wants to move forward with a new Z4 (or Z5), but because of the high development costs, it needs a partner. Enter Toyota, and the already much discussed joint technical venture the two signed. Toyota will have its own version of the new sports car, and BMW is intent on getting its car to market by 2020. Automotive News Europe is reporting that BMW's chief engineer acknowledged last week at Geneva the new Z4 will arrive by the end of the decade. Patience is key here, and we should really just be happy the project is happening at all. The reason? China, where buyers "are not interested in roadsters." Chinese buyers prefer privacy and an open top roadster clearly doesn't allow that.

With so much focus on the Chinese market, BMW will have to rely on North America and Europe for future Z4 profits, which is pretty much the case today. Problem is, the Z4 isn't exactly selling like hotcakes in those regions either.