Can my MJ possession be dismissed?

I was recently arrested for the possession of marijuana and paraphernalia in Essex County, NJ. Two friends and I were smoking in a parking lot. We finished and we began to drive away. The driver turned down a street when a police officer was turning up the street. We were about to turn onto the main road when the officer made a U-Turn and pulled us over, for no apparent reason. He stated that the driver almost hit him with her car then that he smelt marijuana. Knowing the trouble that the driver could get into, I complied and admitted to being the only one who smoked. From there, I was arrested. The driver got a careless driving ticket ($85 and 2 points) and nothing happened to the other passenger. I am twenty years old, never been in trouble with the law and, at this point, I'm defending myself. My only defense is that the cop stopped us illegally and, therefore, violated the fourth amendment. Is that enough to dismiss my case?