This is the 2020 Mazda CX-30, the company's latest subcompact crossover. [credit: Jonathan Gitlin ] SAN DIEGO—The new Mazda CX-30 is a strange and wonderful thing—a subcompact crossover you'll really enjoy driving. Sitting between the diminutive CX-3 and the heftier CX-5, it is an all-new model for Mazda that shares the same new Skyactiv vehicle architecture as the Mazda 3 we tried out at the start of the year.