In your "My Documents" folder, open your 18 Wheels of Steel folder. Use Notepad to
open the "config file". Change the line: 

uset g_console "0" to uset g_console "1" 

While playing, press [~] (tilde) to bring up the console, then type any of the 
following codes: 

NOTE: To open the console, you need to download patch 1.10.

Effect                  Code 
---------------------------------
$100,000              - cheat money
All truck dealers     - cheat dealers
All truck drivers     - cheat drivers
Maximum star rating   - cheat stars