Fiat's bestseller to start 2026 is not its only current model, the 500e electric hatchback.In fact, the bestselling Fiat so far this year is the 500X, a small SUV last offered for the 2023 model year.Fiat sold 71 500Xs, down just 4 percent from Q1 2025, while only 68 units of the 500e were moved in the first quarter, down 85 percent from last year.