We have 1 cheats and tips on PlayStation 2. If you have any cheats or tips for Runabout 3: Neo Age please send them in here. You can also ask your question on our Runabout 3: Neo Age Questions & Answers page.
If you want to unlock everything then you need to get a cheat system like action replay or gameshark.
I don't know any other way to do it except complete all missions.
Hope I helped.