Equip your tractor with the heaviest weight on the back. Your tractor will go now 10 mp/h faster, but it will be hard to turn.
Unlimited money
Enter the directory that corresponds to your latest saved game (for example, "savegame1") in the "\My Games\Farming Simulator 2011" directory. Use a text editor such as notepad to edit the "careerSavegame" file. Change the value of the valid="true" money= line to the desired amount of money.