BMW's display at the 2018 Chicago Auto Show was bewildering. Among the massive lineup of vehicles, the company had at least four obviously different models that were all connected by a common thread. From biggest to smallest, the BMW had a bunch of fastbacks—the 640i GT, X6, 330i GT, and X4—on display. To be sure, having multiple options across a body style is no different than, say, the Volvo XC40, XC60, and XC90, or Audi's Q3, Q5, and Q7. Automakers churn out different-sized cars for different market segments, and there's nothing odd about that.
But the BMW lineup stuck with me enough to bring it up in conversation later with Ars' automotive editor Jonathan Gitlin. BMW is taking this approach to fill automotive niches not even recognized by most other carmakers, and its recent fastbacks are proof. For all that unites them—those four doors and a sloping rear-hatch body style—there's plenty to differentiate. Size, for one thing: simple math tells us the 640i GT and X6 are obviously bigger than the 330i GT and X4. So we decided to review as many as we could to see if the world really needs all the fastback options.
I started with the 640i xDrive GT last March and came away impressed. The GT truly drove like a grand touring car, offering a quiet and posh ride coupled with excellent performance and handling but with a price tag starting well north of $70,000.