Go into forge on a map that has a warthog and a barricade.

All you need to do is spawn a warthog and a bubble shield, but set the bubble shield minimum run time to how many you have spawned.

This is where perfection makes it easier, all you need to do is spawn a barricade and place it so the windscreen of the warthog is showing through the slot in the barricade. The warthog should also look like a turtle with half a shell.

Now turn back into a human/elite, pick up the bubble shield and jump on top of the warthog and put the shield on top of the barricade (this might take a few attempts). Then the warthog should be encased in a shield, then get into the driving seat and drive slowly and the bubble shield will stay with you until it blows up then you just floor it.

This may work for other vehicles but I have only tested it on a warthog.