Owning the physical disc is the only 100% legal way to play.
The 2005 version of on the Xbox 360 is widely considered the "definitive" edition of the game due to its superior lighting, high-definition assets, and exclusive visual effects that were missing from the original PC and PS2 versions. Playing the Xbox 360 Version Today need+for+speed+most+wanted+2005+xbox+360+rom+full