If you have an Xbox one or series whatever both sr1 and sr2 are backwards compatible. Locked to 30fps cause of how the emulator used deals with vsync though. Annoying, cause you could disable the vsync on 360 and have the game run at a unstable AF 30-50fps, but it is what it is.
Or run it on a PC via Xenia. Needed a bit of tinkering to get it running back when I tried it a few years ago, but even then the game ran pretty damn well, and didn’t have any major issues running at 60fps.
Don’t call it forza 4, it makes me and everyone else who played Motorsport 4 feel old…
Though both the real forza 4, horizon 4 and every other forza that had a digital release pre-horizon 5 got removed was just due to expiring licenses for some of the cars and the music. Considering they usually only last 4 years on digital storefronts, with fh4 getting culled after 6 years, I’d give fh5 another year and a half before they stop selling it.