1. Go to a public lobby and invite a friend and find a random vehicle that hasnt got a tracker on it i prefer the baller
2. Upgrade it as much as you want. Don't put a tracker or insurance on it or it would work try not customising it to much on your first try incase you mess it up.
3. You and your friend should get in the car. Make sure you are driver and your friend helping out is the passenger drive over the high overheads of los santos customs in the centre*of los santos customs and you should*see a blue circle for parachuting your going to want to park the car in the middle of the circle.
4. Your going to want to start a ron or gerald mission and as soon as you do that tell your friend to get out of the car and spam right on the d-pad and stay in the parachuting lobby and as soon as you get into the ron or gerald mission back out right away.*
5. The vehicle should still be in the blue circle and what your going to do is to enter the car and then get out and spam right on the d-pad. As soon as you get out of the car tell your friend to leave the mission lobby screen and once they have left tell them to get into the entrance of the parking lot furthest from the blue circle.*
6. once you are loaded into the mission screen you must confirm the setting and invite your friend and you should leave the lobby a quater of a second before your friend accepts the invite on their phone and once you left the job stand still for 3-6 seconds.*
7. After that there should be once of the cars near you. Just look around the area, it normally spawns behind the wall, along the little ramp, along the road near the entrance,or just behind you. The car with a tracker can be soled however the one without the tracker can't be soled but the one without the tracker you can repeat the glitch with so you dont have to customise it again.
Hope it helps you thanks for reading this post have a good day.