they are plug and play,the only thing that i had to do on my kit was to extend the power wire,but i think they send the kit with a longer power wire now....actually the light is much more noticeable during the day also.....It seems like the stock lights work better during the day and the HID work better at night. I really want to get them but want to be sure they are plug-n-play as i dont want to mess with the wiring