Many cars have a simple door light that comes on as soon as the door is opened up. Often times the door light has a reflector of some sort, just to show potential passing traffic that the door is open (so they don't take your door off). While the purpose of these door lights is not to actually illuminate the street itself, the process of swapping out the weak factory glass bulb to a high power LED unit can do a great job of exactly that. Not only do they do a great job at letting others know the door is open, but they cast light into the car, onto the ground, and just look great while doing it!