A good police radar detector can keep you out of unwanted trouble with the law. A speeding ticket can be costly, and too many could cause you to lose your license. In some cities, police radar detectors are illegal, and using one could get you into far more trouble that getting a ticket would. So make sure you know the local laws before you buy. The best police radar detectors have a long range so you'll know if there are police present anywhere in your area. Set one up, and find out how easy it is to protect yourself from a speeding fine.