Go to forge on any map.

Have 1 person fly up in the air.

Have them spawn any vehicle with respawn rate on 10 and set it to instant respawn.
Then before you let it go have the other person spawn a rocket launcher with at least enough shots to destroy two of the vehicles.

Then gently place the vehicle on the ground.

The person with the rocket launcher should then drive it away.

Then the person who spawned the first vehicle should spawn another without moving their person at all (it should spawn so the blue dot is in the exact same place as the first one).

Put this respawn time on 180 and instant respawn.

Then the guy with the rocket launcher should destroy the vehicle he drove away first. Then the other one.

As soon as a vehicle respawns the guy with the rocket should get in and drive away.
Then when the other respawns the forge mode guy should pick it up.

The guy on the vehicle will then have no gravity (if you were the one in forge mode you can never leave forge mode - and if you were the human you can't enter forge mode. If you do the glitch might not work).

This works best with Ghosts on Valhalla.