Im sorry, but in short, if you hit the car in front, then that was your fault for not paying attention, and/or driving too close to the car in front. So unfortunately for you, the law is within its right to prosecute you for driving without due care and attention. You need to learn from this, as it could have been a whole lot worse if you had badly injured or, god forbid, killed the occupants of the car in front. You should always drive in a safe manner, that you are always able to act and react to any situation that is happening in front of you under most driving conditions. The HEAVIER the traffic, the more distance you put between you and the vehicle in front. My expertise in this matter is that i have been a hgv-1 driver for nearly 25 years and have been driving for 31 years. I hope this helps to answer your question and to understand the situation that you have got yourself in. Good luck and take care on the roads, Mike.