Or look it up on eBay. However, it may not work. We have a 18 crosstrek premium. It had a 6” HU like yours. However, when I put in the 8” in our crosstrek, the original single usb works with android phone BUT will not connect with iPhone. I end up have to get a 2 ports usb for the 19 Subaru (not sure what model) off the ebay with 2.1amp output. Works great now. That also fix the battery drain issue. However, swapping out the usb/aux is not an easy job. You will need to take out the center cup holder section to get to the usb/aux port. I broke the single usb/aux port before i realized I had to take the cup holder section out.
Aye, was hoping it might be otherwise, but afraid it aight so... Trip to the dealer it will be then - will try to get ahold of that double usb port from the limited at the same time.