Why Did BMW Discontinue Hardtop Convertibles?

BMW makes fantastic convertibles like the Z4, the mild hybrid 4-series, and the 8-series. Open-top driving in what BMW calls "The Ultimate Driving Machine" has few replacements outside of riding a motorcycle. I, personally, found the 2024 BMW Z4 M40i to be one of the best cars I drove all year. Sadly, convertibles seem to be getting rarer with each passing year. Even rarer is the hardtop convertible, with really only the Mazda Miata RF surviving until now. In years past, you could buy a number of different folding hardtop convertible Beamers, now that's not the case. The BMW 4 Series did away with the hardtop in 2020.

In a press release from 2020 for the second generation BMW 4 Series convertible, BMW stated outright why it doesn't favor the hardtop convertible idea, saying: "The most noticeable change from the previous generation is the switch from hardtop to newly designed soft-top, which brings many benefits including weight reduction, greater cargo space, and a lower center of gravity for improved handling." I've reviewed a number of BMW performance cars like the newest generation of M5 and the 2025 2-Series and I can confidently say that BMW is dead serious when it comes to lowering the number of compromises it has to make when it's engineering a car.

Designing a convertible goes a lot further than just chopping the roof off and calling it a day. There are a lot of structural decisions to consider, all of which impact performance. BMW did the handling-focused math, and decided that cutting the hardtop was the best course of action. Soft-top convertibles allow the folded roof to fit into a smaller space than a hardtop. That not only allows for more storage space (leading to a more useful overall vehicle), but also provides for more structural rigidity in the body of the car. A more rigid vehicle is a better handling vehicle. 

BMW adds: "The panel bow soft-top (of the 2021 M4 Convertible) is some 40 per cent lighter than the predecessor car's retractable hardtop." That much of a weight savings, even over a single part is huge. If BMW really wants to call itself the maker of "The Ultimate Driving Machine," then it has to do all that's within its design power to make a car handle the best it can. To BMW, a hardtop convertible was an unacceptable compromise.