You have to remove your halogen housings with bulbs and replace with these housings (which will have the main bulbs included) and HIDs for the xenons. The system is plug and play. Any shop with good knowledge of E90s will know how to complete the install cleanly.
Originally Posted by tolbert86
so you pretty much just change out the whole head light and they will work? I have an 07 328i with regular halogens and looking to upgrade.