Midnight Club L.A. psp help!?

I have a skyline and a 240X completely upgraded and i'm stuck. Is there a way to get money rather than racing? I want a ducati because i read some forums and they said if I drive 80000 meters on two wheels, i unlock the bikes. None of the bikes were unlocked even though I drove 80000 meters. How do I get ducati then? I also, read some forums that told me that I can get money without winning races. This idea was about selling a car u already have and then buying it again making a profit. In this case i wouldn't lose my modified car.