Many automakers, especially European luxury brands, have expanded the availability of so-called “four-door coupes.” The vehicles take familiar crossover and sedan shapes and remove some of their practicality in the name of style, with heavily sloped roofs and less headroom than comparable models. BMW is as guilty as any company, as it has been busy making the oddball vehicles for years. The X4 was one of the first, and BMW’s M division got ahold of early models to make the M40i variant. The hot crossover first got the M treatment in 2016 with a 355-horsepower turbocharged six-cylinder engine. Today’s M40i slots into the middle of the X4 lineup between the base X4 xDrive30i and the wild X4 M.