something more scary...be careful when buying a used car or rental car, heck, this even goes for new cars. The previous person(s) in possession of the car, could have transported drugs in the car. Think about getting stopped at one of these checkpoints, you've never been involved with drugs in your life, and the dog alerts on the truck of your car. Try and convince these police officers you've never done drugs in your life.
Just a suggestion, take any car you buy to your local police station and have them check the car for drugs. If you can, get them to verify the results in writing. Until we return to sanity in this country, an ounce of prevention is worth a pound of cure.