Topic on Talk:GRID Autosport

If you weren't able to redeem the two free DLCs before they were delisted from the Steam store, you will not have the authorization to download the files from those DLC depots, and will instead need to download the files from the "Linux - GRID Autosport - Content" depot or the "Mac - GRID Autosport - Content" depot. The high-resolution PSSG files and Demoman Derby NeFS archive are not OS-specific, so there are no compatibility issues that arise from downloading these 627 files from either the "Linux - GRID Autosport - Content" depot or the "Mac - GRID Autosport - Content" depot and using them with Windows.

In this example, I will be using the "Linux - GRID Autosport - Content" depot to get the DLC files for a Windows installation. These instructions would require alteration if using the "Mac - GRID Autosport - Content" depot instead (you would need to change the depot & manifest IDs, as well as the DLC file paths), and there is no reason to prefer the macOS depot over the Linux depot (the needed files are identical; I've verified this).

.NET Runtime 6.0 is a dependency of DepotDownloader. You don't need to install the .NET SDK, just the runtime (you don't need the ASP.NET Core Runtime or the .NET Desktop Runtime either, just the basic .NET Runtime for Windows). Download the appropriate package for your system (e.g., x64).

Download DepotDownloader. Extract the depotdownloader ZIP archive to a location of your choosing. Install .NET Runtime 6.0 (e.g., .NET Runtime 6.0.14) if it is not already installed.

The vast majority (11,547) of the files in the "Linux - GRID Autosport - Content" depot are not relevant for the free DLCs, and should not be copied to a Windows installation. To save from having to download the entirety of the "Linux - GRID Autosport - Content" depot and then delete the unwanted files, you can specify which files you want to download (this will also save ≈ 11.6 gigabytes worth of downloading). To do this, in the same directory where DepotDownloader is located, create a text file named dlc.txt. For example, if you extracted DepotDownloader to a subfolder in your Downloads folder named "depotdownloader-2.4.7", then you would create the dlc.txt file in %USERPROFILE%\Downloads\depotdownloader-2.4.7\.

Enter (just copy and paste) the following 627 lines into the dlc.txt file, then save the text file and close your text editor (click the Expand toggle below to see the DLC file list):

Exit Steam if it is currently running. Open Command Prompt. In Command Prompt, change to the directory where DepotDownloader is located. For example, if you extracted DepotDownloader to %USERPROFILE%\Downloads\depotdownloader-2.4.7\, then in Command Prompt enter cd /d %userprofile%\downloads\depotdownloader-2.4.7.

Enter the following command in Command Prompt (change steamusername to whatever your Steam username is):
dotnet depotdownloader.dll -app 255220 -depot 255238 -manifest 839216417523198144 -filelist dlc.txt -username steamusername -remember-password

The default download location is a subdirectory named depots in the depotdownloader directory. Continuing with the previous example, that would be %USERPROFILE%\Downloads\depotdownloader-2.4.7\depots\. If you wish to specify a different download location, you will need to add -dir followed by the location of your choosing to the previous command.

You will be prompted for your Steam password. Once you have entered your password, if you have Steam Guard turned on, you will be prompted to enter your 2FA code. If you haven't secured your Steam account with Steam Guard, you really should.

Once the download is finished, you can verfiy that everything has been downloaded by selecting both the cars and download directories and then pressing Alt+Enter on your keyboard or right-clicking them and selecting Properties from the context menu (using the previous example, these two directories would be located in %USERPROFILE%\Downloads\depotdownloader-2.4.7\depots\255238\4011980\share\data\). There should be 627 files and 713 folders, and the size should be 4.62 GB.

Copy the cars and download directories you just downloaded over to your Steam installation of Grid Autosport (e.g., %ProgramFiles(x86)%\Steam\steamapps\common\GRID Autosport\). Windows will prompt you to confirm that you want to merge the directories. Select Yes. If you don't plan on using DepotDownloader again, you can delete it, and you can uninstall Microsoft .NET Runtime 6.0 (e.g., 6.0.14) if you don't have any other applications that use Microsoft .NET Runtime 6.0 (i.e., if you only installed it to run DepotDownloader).

You will still need to download and install Koalageddon. Once installed, run the Koalageddon wizard to install the platform integration for Steam. You can now restart Steam. If you ever uninstall Grid Autosport, and thus no longer need to access the free DLCs, you can later use the Koalageddon wizard to remove the platform integration for Steam. Like I said, Grid Autosport uses VAC, and I can't guarantee that Koalageddon won't trigger VAC, so I would disable VAC. To do this, add -insecure to your launch options for Grid Autosport. Right-click Grid Autosport in your Steam library, select Properties, and in the General section, add -insecure under the text "Advanced users may choose to enter modifications to their launch options." This may prohibit multiplayer if Codemasters doesn't offer VAC-free multiplayer servers, but you will still be able to play singleplayer.

You can quickly test if the DLC content has been enabled in-game. From the Main Menu, go to Custom Cup, change Vehicle Discipline to Party Mode, and Demoman Derby should now be a selectable option for Vehicle Class.