Those look the same as my
gen-2 CTS-V brakes, specifically this picture:
15in (380mm) 2-piece rotors, 6-pots calipers, also shared with the 6th-gen Camaro ZL1.
If the same thing, then I'm curious as to if they are direct-fit with no modifications. After all, we share wheel bolt pattern amongst other things, as I had to find out when I was trying to source wheel adapters, so I wouldn't be surprised if they just bolt right on.
More people buying these things from GM for their Nissan S13s and Subarus, then cheaper parts for me when it's time for my own replacement!
*edited to add* yes, they are good brakes from what I can tell. My car weighed in at 4250lbs at Mission Raceway, and they repeatedly hauled the whole thing down from 115mph to "paddock speed" all night long. Also, brake bleeds are a total breeze compared to my BMWs, but that might be a Brembo thing in general.