This is a good idea, but what if you don't have extra o rings?
I had this same problem a while back when I had hids in stock headlights, and I just twisted the bulb opposite the way it twists into the headlight, so the wires would be pulling it tightly in the headlight where it twists in..... like say it inserts into the headlight twisting to the right, so I twisted the bulb a lot to the left so the wires were trying to pull it back to the right, holding it there just enough to not move.
I didn't do it enough to hurt the wires, but I'd do this extra o ring if I could instead of twisting any wires.
I had this same problem a while back when I had hids in stock headlights, and I just twisted the bulb opposite the way it twists into the headlight, so the wires would be pulling it tightly in the headlight where it twists in..... like say it inserts into the headlight twisting to the right, so I twisted the bulb a lot to the left so the wires were trying to pull it back to the right, holding it there just enough to not move.
I didn't do it enough to hurt the wires, but I'd do this extra o ring if I could instead of twisting any wires.