Hey guys new to this site. I just bought my 2015 wrx base model. I was curious if I'm able to upgrade the head unit from out of a newer model into mine. And also if the speakers from Newer model will just fit right into my car.
The 2015 is very easy to upgrade the head unit, since it doesn't have the Starlink and all that stuff connected behind. I replaced mine (also a 2015) with a Kenwood DDX9906XR, I was mainly looking for Wireless CarPlay and capacitive touch with decent resolution (720p). It has iDataLink Maestro support so it will work with your wheel controls if you also buy the Maestro RR interface. I also got the iDataLink SU1 harness to ease the connecting job a dash kit and a Metra AX-TOYUSB cable to be able to use the USB port from the car.
I haven't installed it yet because my car is getting a new motor, but I connected everything and it sounds good and seems to work great.