One of two models offered by Scion in its first year of production, the xB was a compact multipurpose wagon powered by a 1.5-liter, double-overhead-cam four-cylinder engine that produced 108 horsepower. A five-speed manual transmission was standard, while a four-speed automatic was available as an option.

The Base model was the only version of the xB available for 2004. Standard features included air conditioning, power steering, power windows, power door locks with remote keyless entry, power exterior mirrors, a tilt steering wheel, and a Pioneer AM/FM stereo system with a CD player and MP3 connectivity. Other features included antilock brakes, traction control, and stability control.

Beyond the standard features, a seemingly endless list of dealer-installed appearance and sound system upgrades allowed buyers to further personalize their xB.

The 2004 Scion xB was tremendously successful in attracting the younger audience that Toyota, which built the Scion, was aiming for, but many 30+ shoppers also bought the xB. Owners have been very satisfied with the lengthy list of standard convenience features, along with the availability and flexibility of the options. Gas mileage and reliability also are listed as favorite features.

Many drivers caution that the xB best serves the needs of urban commuters, and driving it for extended periods of time can be uncomfortable. While the xB's seats are comfortable, the car's stiff suspension and light weight can lead to a very intrusive road feel.