If you don't trust downloads, you can use cheats to generate your own great save data. By installing (part of Custom Firmware), you can enter codes to unlock everything instantly on your own cartridge.
If you don't want to download someone else's save data, you can "cheat" your own. From the main menu, hold the and enter these codes to modify your current save: cars 2 psp save data
The PSP uses a proprietary Memory Stick Duo. These cards are notorious for data corruption after 10+ years. If your childhood save vanished, downloading a replacement is the only way to get back to the Piston Cup. If you don't trust downloads, you can use
Here are a few tips and tricks to keep in mind when working with Cars 2 PSP save data: From the main menu, hold the and enter
Now, grab that save data, select Lightning McQueen, and hit the boost pads. The Piston Cup awaits.