But Elias wasn't doing this for the achievements. He was doing it for the cars.
: Exclusive to those who pre-ordered the physical 360 version. Note : Major expansions like Storm Island or the Porsche Expansion were never released for the Xbox 360. Installation Guide for RGH/JTAG Forza Horizon 2 Dlc Xbox 360 Rgh
If you seek the complete Forza Horizon 2 experience (including Storm Island and all 10 car packs), you must play the (via backward compatibility). The Xbox 360 version, even on RGH, will always be a cut-down, engine-limited port. But Elias wasn't doing this for the achievements