Unveiled in September 2003, the second-generation Prius (XW20) transformed into a five-door liftback featuring a teardrop aerodynamic shape achieving a Cd of 0.26. Its wheelbase expanded by 150 mm (to 2700 mm), reclassifying the Prius into the mid-size segment. Innovations included keyless Smart Entry with push-button start, a central touchscreen infotainment panel, and a drive-by-wire gear selector. Engineers paid meticulous attention to structural body rigidity, minimizing noise, vibration, and harshness levels while enhancing cabin material quality. The refined chassis architecture delivered excellent ride comfort and predictable handling characteristics across both urban streets and high-speed highways.

The upgraded Toyota Hybrid System II operated at a higher system voltage (500V) and paired a 1.5-liter 1NZ-FXE engine (77 hp) with a 68 hp electric drive motor to generate 110 total horsepower. An electric A/C compressor was introduced, allowing climate control operation when the petrol engine was off. A mid-cycle refresh in 2005 updated headlights and audio options. XW20 production ran until 2009. High levels of active and passive safety were corroborated by outstanding crash test results and comprehensive driver assistance technologies. Thanks to exceptional mechanical endurance and robust powertrain engineering, this generation earned global acclaim across all major automotive markets.