For my headlights I added an invisible light blocker preventing the "real" lights from shining through, and then faked the headlight beams with IES lights positioned just outside the headlight glass. Then it's just a matter of finding an IES that looks right for your headlight type. I just eyeballed it, since I wouldn't know where to start to find an exact headlight spec IES. You could also use IES profiles for the spill near the car, while using larger, more normal beams of light for the primary focus.