The Mazda 3 (known as the Mazda Axela in Japan) is a compact car manufactured in Japan by the Mazda Motor Corporation. It was introduced for the 2004 model year, replacing the Mazda 323 Protegé and Astina (BJ Model). A more performance-oriented version of the Mazda3 is marketed as the Mazda3 MPS in Australia/Europe and as the Mazdaspeed3 in North America.
The Mazda3 has been generally well-received by the automotive press for its performance, handling, styling and interior, with some describing it as feeling like a more expensive sport sedan despite its value-oriented price. Some criticisms have included fuel economy and crash test results (only receiving four out of a maximum five stars from the EURO NCAP Safety Testing Programme) the latter of which was rectified by making six airbags standard. A factory fitted sunroof was optional for the 2004 model in Australia.
The Axela is based on the Ford global C1 platform, shared with the latest European Ford Focus and Volvo S40. Based on the styling of the MX-Sportif concept car, the Axela is available in two body styles, a four-door sedan, and a five-door hatchback, branded the Sport version in Canada, Japan, and the United States.
Front suspension is by MacPherson struts, with coil springs and an anti-roll bar. Rear suspension is a Ford-Designed "E-link" multi-link suspension, with four locating links per wheel and an anti-roll bar, suspended on coil springs that are mounted inboard of the shock absorbers to reduce suspension intrusion into the cargo area.
Disc brakes are standard at all four wheels, with ABS standard. Wheel and tire sizes vary with model, from 15 in on base models to option 17 in wheels on upper-level models.
All 3 models use the inline-4 Mazda MZR engine, with various types, displacements and outputs including the MZ-CD turbodiesel, depending on model and market. Transmissions are a five-speed manual transmission and a four-speed automatic transmission; since the 2006 model year, a five-speed automatic is optional on models with the 2.3 L engine. This transmission has now been made standard on the 2.0 L engine in Japan (FWD models only), as part of a minor facelift in early 2008 which includes different front/rear bumper designs, new wheel designs and body colours, stiffened chassis, and better interior materials. The MPS / Mazdaspeed version is only available with a six-speed manual transmission.
Mazda redesigned the front bumper on the SP23 and also introduced the Luxury Pack option for the top model which included a black or red leather interior and a 7 speaker BOSE Audio system. Due to ADR rulings in chassis strength, the option for a sunroof was dropped by Mazda for the 2005 range.
For the 2006 model year, Mazda added variable valve timing and variable-length intake runners to the 2.0 L engine resulting in a power increase to 150 bhp (112 kW; 152 PS). The automatic transmission used in Mazda3 with the 2.3 L engine was changed from a four-speed to a five-speed design. The colour palette was also simplified in 2006, with the deletion of Canary Yellow. Dynamic Stability Control (DSC) safety technology is now standard across the range
2006 also saw the introduction of the MPS 3 (Mazdaspeed3)- unveiled at the Geneva motor show, the latest of the Mazda Performance Series. The MPS 3 has been mated with the turbocharged 2.3-litre four-cylinder from the Mazda6 MPS with the smaller body of the Mazda3, liberating 190kW and a stupendous 380Nm of torque and will dash to 100km/h in a mere 6.1 seconds.
Source: http://www.ozmazda.com/index.php/mazda_models/mazda3_axela.html
More about Mazda 3 you can read on above site, I will focus on Mazdaspeed3 / Mazda 3 MPS model.