New for 2004, the Mercedes-Benz E500 wagon was equipped with the 4Matic all-wheel-drive system, which provided improved handling, stability, and traction in all types of driving conditions. The wagon also came with third-row seating that folded down to provide additional cargo space.
Power for the E500 wagon was provided by a 5.0-liter V8 engine that produced 302 horsepower. The engine was linked to a new, more efficient seven-speed automatic transmission, which was designed to help improve gas mileage as well as acceleration. The transmission was equipped with the Touch Shift feature, enabling the driver to upshift and downshift manually by nudging the shift lever left or right.
The E500 wagon was well-equipped with both luxury features and high-tech mechanical systems, including a self-leveling system, anti-lock brakes, traction control, and an Electronic Stability Programming (ESP) anti-skid system. It also came with the automaker's TeleAid emergency communication and assistance program.
Other standard features included leather seats with power adjustment in the front, wood interior trim, a leather-trimmed steering wheel, multi-zone automatic climate control, dual front and side airbags, power windows, power exterior mirrors, cruise control, and an AM/FM audio system with a CD player.
A new DVD-based navigation system was among the options. Other options included Dynamic Drive seats that adjusted automatically to support the driver under heavy cornering, a twin sunroof with power sunshades, and a smart cruise control system that automatically adjusted the vehicle's speed to maintain a set distance from the car it followed.
While drivers noted that the 2004 E500 wagon delivered quick acceleration, a smooth ride, responsive handling, and plenty of creature comforts, a number of drivers reported having numerous problems with the car, including problems with the transmission, brakes, and electrical system. Many also noted that the car was noisy and unreliable. However, the wagon's 4Matic all-wheel-drive system generally drew good marks from drivers, especially those living in northern climates.