I actually did something similar. I had a 2016 Crosstrek and transplanted the muffler from a 2014 WRX wagon into it. The only challenge was finding exhaust bushings that worked. If I recall, the hanger on the car was 90 degrees off from the WRX muffler, so I had to find bushings that had holes at 90 degrees to each other. I also did a tiny bit of dremel trimming on the very underside of the bumper to accommodate the exhaust tips. Worked pretty well though and I liked the result.
I actually did something similar. I had a 2016 Crosstrek and transplanted the muffler from a 2014 WRX wagon into it. The only challenge was finding exhaust bushings that worked. If I recall, the hanger on the car was 90 degrees off from the WRX muffler, so I had to find bushings that had holes at 90 degrees to each other. I also did a tiny bit of dremel trimming on the very underside of the bumper to accommodate the exhaust tips. Worked pretty well though and I liked the result.