BMI performance Direct is proud to carry the Subaru OEM Vortex Generator. The purpose of this roof-lined vortex generator is to channel the airflow so that it hits the top of the rear spoiler to improve both aerodynamics and downforce. This is why you see vehicles that come from the factory with a larger rear spoiler, will also come with some sort of vortex generator on the back of the roof.
FITMENT NOTE: 2017+ WRX and STI Models will have 2 different antenna options depending on entertainment package (Starlink). This will fit the SMALLER, non-starlink, 8.5" long antenna. The larger 9.125" antenna will require the later model vortex generator.