When Need for Speed: Underground Rivals arrived on the PlayStation Portable in late 2005, it carried with it the DNA of an era: neon-lit streets, throbbing aftermarket beats, and the intoxicating promise that every race could change your reputation. The PSP, Sony’s first handheld to offer near-console horsepower, let players carry that rush in their pockets — and with it came a small, critical artifact of progress: the save file. The unassuming block of data tucked into the Memory Stick Duo became a ledger of triumphs and defeats, a record of the player’s garage, upgrades, and hard-earned street cred.