Subaru Impreza WRX STI The WR car based on facelift new Impreza. Since 2003 FHI has been strengthening its support of the Subaru World Rally Team (SWRT), which takes part in the FIA World Rally Championship (WRC). FHI and SWRT have been closely working to improve on vehicle performance in rallying, to accumulate know-how with the feedback from rallying experience, and to apply that know-how and technology to the production of the Impreza base model. The Subaru Impreza WRX STI (formerly STi, officially changed in 2006) is the highest standard-edition trim in the Subaru Impreza line. In the late 1980’s, Subaru created the Subaru Tecnica International (STI) division to coordinate development for the FIA World Rally Championship and other motorsports activities. After the company had grown, the division was used to create high-performance consumer versions of the Subaru Impreza WRX , an AWD car with a turbocharged flat-4 engine, leading to the development of the Impreza WRX STi. Subaru has used a race-prepared version of the WRX STI as its rally platform since the model trim’s creation.