It would probably help if you stated what system you're playing on.

hey i have been looking for days now to see where the cargobob spawns and cant find it anywhere so i was wondering if any of you know where it spawns

Cargobobs can either spawn at the military bas ...

Make sure you're out of the police's vision. Meaning the radar will stop flashing red and blue and your stars will be flashing. Accept the mission as soon as this happens and then keep doing it.

Y ...

How exactly are you going about it? He should be able to drive it right into his garage.

Have him accept a mission while in your car and then have him drive it in. After he gets out of the car end ...

I actually have the same problem myself. No aircraft spawns for me once I am in the glitch. I even tried waiting an entire morning in a different location and came back to the airfield with not a sing ...