Diode Dynamics Tail as Turn + Backup Module | 2015-2021 Subaru WRX/STI (DD3012)2015 2021 Subaru WRX STi Tail as Turn Module Custom Appearance. This kit will convert the LED tail light on your 2015 2021 Subaru WRX STi to also function as the turn signal. This kit will instantly customize your vehicle for a much more modern appearance on the road! Additional Backup Lights. Also available with the kit, you can convert the old turn signal socket to an extra backup light. With double the number of backup lights, you will add much