[Valley Rider]

You asked about the plastic cover. I assume you mean the black cover about 3-4" in diameter. I cut a 1" hole in the black cover to accomodate the boot provided in the HID kit. Be careful to drill the hole in the correct location - it should be off center and directly behind the bulb housing. WHen lined up correctly the HID assembly and boot fit nicely in the 1" hole. If it isn't lined up correctly you may not get the black cover back on without hogging out the cover and losing your seal. Hope that helps.