DiRT 3 and its Complete Edition were removed from the Steam marketplace in early 2017. This was likely due to the expiration of licensing agreements for the vehicles and music featured in the game.
The original download size is approximately 14.09 GiB , requiring about 27.37 GiB of disk space. Safety Warning DiRT 3 Free Download
Be extremely cautious of websites claiming to offer a "Free Download" for DiRT 3 now that it is delisted. These are often unofficial "abandonware" or "repack" sites that may bundle with the game files. Always use updated antivirus software if you choose to explore these third-party sources. DiRT 3 and its Complete Edition were removed