It gets tricky with the high-end systems though. The HK in the F30 3er was a mess since the whole thing was proprietary fiber optic wiring. There was an expensive aftermarket wiring harness you could buy to put in a different amp, but it was kind of a mess and your options were really limited since the harness was built for one aftermarket amp. I didn't want to get into that kind of nonsense, so I ended up going the Bavsound route and replaced the speakers, but it never quite got to where I wanted it. There's a huge Bimmerfest thread in the F8x M3/M4 board (since most of the parts are shared) where some guys with audio engineering backgrounds tried to calibrate the EQ to get the system somewhere close to being flat, and I was deep down that rabbit hole, but it was basically impossible... I really hated that car: it was beautiful, but it never did any of the things I wanted it to, and I just kept throwing good money after bad chasing the hope that I could make myself love it.
But yeah, to
@arod221's point, I wouldn't hold out hope that you can just easily swap things out. Especially with the integrated infotainment systems in newer cars, things get complicated. Everything's too tightly linked. May just have to cross our fingers that the AKG is good enough.