Downloading "free" versions of paid games from third-party sites like the one mentioned carries high risks:
If you are looking for a review of the actual game play, DiRT 3 is widely considered one of the best rally racers ever made. dirt-3-complete-edition-free-download-pc-hienzo-com
Some legitimate third-party retailers may still have leftover digital keys (e.g., Humble Bundle or Fanatical), though these are becoming rare. Downloading "free" versions of paid games from third-party
Since the game is no longer on Steam or the Xbox Store, here is how you can play safely: Humble Bundle or Fanatical)
DiRT 3 was delisted from official stores (like Steam) due to expiring car licenses, but downloading it from unofficial sites is still considered copyright infringement.