The X4 is a specialized spin-off of the popular 3-Series sedan. The X4 trades a trunk for fastback styling, a hatchback and higher ride height. With the rear seats up, the interior is similar in size to the sedan, however the hatch and fold-down rear seats offer a larger and more accessible storage area. BMW's xDrive AWD is standard on all models. Powertrain choices include 2.0l four-cylinder (xDrive28i) and a 3.0l inline six (xDrive35i). The X4 is a niche vehicle that will only appeal to someone looking for something different. The 3-Series offers stronger performance credentials and a wider array of powertrain choices.