Answer:
The one that is not a good procedure is the last one:
slam on your brakes to get the attention of the driver tailgating you.
Explanation:
The other procedures mentioned are quite effective if you wish to avoid being rear-ended by another vehicle. By keeping a good distance and signaling what you are about to do, you give the other driver enough time to respond. In traffic, any abrupt changes or decisions reduce the time to think and respond in a defensive manner. If you slam on the brakes, you make your car come to a sudden halt, which is certainly not expected by the other driver. If he is driving is close behind you, or if he's not paying that much attention, chances are he'll only respond when it is too late. Thus, slamming on your brakes is not a good procedure to avoid being rear-ended.
