Mazda's rotary-engine-powered sporty car is a 4-passenger 4-dr with rear-hinged rear doors that do not open or close independently of the fronts. Conventional engines use pistons that move up and down in cylinders. A rotary has triangular rotors that spin inside oval housings. The RX-8's displaces 1.3-liters and has 197 hp when teamed with a 4-speed automatic transmission, 238 hp when linked with a 6-speed manual. The automatic includes a manual-shift mode using steering-wheel paddles or floor lever. Manual-transmission RX-8s have 18-inch wheels, stiffer sport suspension, and a limited-slip differential. A Sport Package option for automatics replaces their 16-inch wheels with 18s and adds the stiffer suspension. ABS, front side airbags, and head-protecting curtain side airbags are standard. An uplevel Shinka model was added during the model year. Standard xenon headlights and a suspension tuned for ride comfort are unique to Shinka. Standard on Shinka and available for base models is leather upholstery, antiskid/traction control, satellite radio, and a power sunroof. A navigation system is available for all RX-8s. We have not yet tested the Shinka. Mazda says a revised 2006 RX-8 will arrive early in the calendar year.