If the Zaibatsu Corporation don't have a bad relation with you, this mission will not be hard.
First you must find the parked Z-Type. A pink arrow will show the Z-Dealers' location.
This Places are:
- Train Station in Bayano;
- Hospital in Bayano;
- Escobar Power Cores (if the Zaibatsu's hatred towards you is big, you'll have a hard time: there will be many of them, carrying Rocket Launchers)
Once all the Z-Dealers are in the car, deliver them to the Crane. As a reward, you will get 40.000$.