In the 5 years that Subaru has made this generation of WRX and STI, the head unit has changed multiple times but never really impressed us with its sound quality or overall user friendliness. 2019 and up cars got Apple CarPlay and Android Auto support but older ones like this 2017 didn't have it. We've done our fair share of Impreza/WRX/STI head unit upgrades this year and for this car we put in Pioneer's latest DMH-W4660NEX.
This is about as nice of a head unit we'd recommend in a traditional double din chassis size. The interface is snappy and the wireless Apple CarPlay is very easy to setup. There's no built-in maps but with wireless Android Auto/Apple CarPlay, most people won't miss it. Google Maps, Waze, and Apple Maps are all way more user friendly than any offline maps that come built-in on head units anyway.
Because this system has wireless CarPlay, we ran the USB to the glovebox. We did not use a USB retention harness to reuse the factory USB as in our experience, the factory port is too slow and incompatible with Android Auto/Apple CarPlay. For steering wheel controls, we used the Maestro SW which was able to retain most of the 11 steering wheel buttons.
We did not use the iDatalink Maestro RR although this vehicle is compatible with it. If you have a WRX or STI in the Sport Tech trim which includes the Harman Kardon amplifier system, the RR is a must have accessory. The RR will also add features like engine diagnostics and gauges, front camera control, and more. It's a powerful system but if a front camera and amp retention are not needed, the OBD features alone aren't really worth it. We did use the Maestro SU2 harness to retain the backup camera however, do note that a 6V step down is required for the camera to properly function.
On top of the new head unit, we also added graphite Alloygator wheel protectors. These offer a bit of contrast to the vehicle and helped cover up some of the light curb marks this car had collected over the past 3 to 4 years.
Contact us today if you are looking into Apple Carplay, Android Auto, or simply improving your vehicle's sound system!