For purists: Focus on the "Side Jobs" (Casino, Dragon Tail, Truck Heists). Completing all of these unlocks the majority of cars naturally. It’s more rewarding, but time-consuming.
Getting a pre-completed save file for (2009) is a great way to jump straight into the high-octane car chases or replay your favorite missions without grinding through the early levels. 🏁 Where to Download Save Files
For PC gamers, the situation is more complex. Wheelman was a console port that was notoriously buggy on PC. Many modern gamers play this title via emulation (using RPCS3 for PS3 or Xenia for Xbox 360) because the PC version has compatibility issues with Windows 10 and 11. Transferring save files to emulators is a common practice to test game performance or bypass bugs that might prevent progression in the emulated environment.