Press ~ during game play to display the console window. Enter one of the
following codes to activate the corresponding cheat function.

1. Enter the Steam control panel then select the "My games" tab.
2. Right Click the "Left 4 Dead 2 Demo" option then select "Properties".
3. Select "Set Launch options" then enter -console and accept it.
4. Start the game, and the console window should now appear.
5. Enter bind p toggleconsole as a console command. Click and close the
console window and start a single player game.
6. Press "P" during game play to display the console window, then enter
sv_cheats 1 to enable cheat mode.

Press [Ctrl] + [Shift] + 1 to display the console window. Enter one of the
following codes to activate the corresponding cheat function.

В главном меню выберите "Настройки", "коды", "Введите новый чит",
Затем введите один из следующих кодов для разблокирования соответствующей
чит опции:

1. Go to "documents",
2. Go to "German Truck Simulator",
3. Go to "config" or "config.cfg",
4. Open it with "Editor" and save that for all config-files,
  then look for:

Start the game with the "-DEVMODE" command line parameter. Then, press
one of the following keys during a game to activate the cheat function.
Note: When in developer mode, all levels will also be unlocked.

В меню Unlockables вводите следующие коды