[displacement4me]

How do you deal with the cap that was removed in order to put the new HID bulbs in? do we need to find a new backing? or just leave it open?

If you look at that video posted on page 1 or 2 or whatever is shows. Thread it out, drill it safely for the grommet lip, thread it back in and done. I'd be 'hoping' that with the grommet hole done right that the rubber seal around the wires would still be tight enough to keep the back of the head light mostly dust free.