http://dronesurvivalguide.org/ Maybe this belongs in the Survival forum ... probably not. In WWII posters of enemy aircraft were used to help with civil defense. Print your poster from here.
Putting that reflective poster on your car roof would probably result in a missile fired at the car. The target-choosers would interpret the reflective device as indicating knowledge of drone operations and attempting to avoid a successful strike. Both indications would identify the vehicle as a target. Now, if you could get everyone with a vehicle in the area to mount a reflective poster on the roof, it might help. :laugh:
Snake oil. However, it may be a good idea to sell some of these survival guides to the Taliban and Al Qaeda. Then in a few months lets ask how it's working out for them.