Some LED conversion kit bulbs can be too large to fit under the OEM headlight dust cap. One of the possible solutions is to drill a hole in the plastic dust cap to allow the LED bulb body stick out of the dust cap. Another solution is not to put the dust cap back on the light, but that allows water and other elements entering the headlight. Our prefered solution is to use after-market rubber dust caps which are flexible, expandable, and some have pre-defined holes in them to make your LED conversion kit installation that much easier.