You know those lights that police have.., that they can aim with and use to illuminate whatever they want, like an address, and that are mounted on top of their car.., how or where can I get something like this?? 

It would be great to be able to illuminate a sign when driving through some darkened part of the woods., I've tried a bright flashlight, but it reflects back at you from the glass if you're holding the flashlight while inside the car..,