Does my case have a chance of being dismissed because of the lack of evidence or could I possibly win the DMV hearing?

On New Years Day, I had just arrived at my house at around 3:50 a.m. when I saw my father's truck speeding down the street. I thought my sister was driving but when I went inside my house everyone was home so I went after the truck. I caught up to the truck and when I pulled up next to it I looked at them and they just gunned it and took off. I called the police to report what was going on. I continued pursuing the truck and and a few minutes later, an officer took over and stopped the truck. I parked by the scene and then an officer told me to drive towards him, the officer greeted me with suspicion and arrogance. I didn't know why until I looked at the people who took the truck and it was my cousin and his friend. Apparently my sister had them over, they told the officer they borrowed the truck from my father who was in Mexico at the time, and that I was delusional and on drugs. I told them that wasn't possible because my father was out of town. After that I was checked by the officer to see if I was under the influence. He performed two test on me, first he had me follow the tip of his pen and then he had me close my eyes and count to thirty. He then asked me if I had smoked marijuana and I answered "yes hours ago". He asked how much I smoked and I said "I took two hits" and he said "I think you've smoked four bowls". After this I decided to remain silent and he arrested me for DUI of marijuana. I didn't smell like marijuana and I didn't have any on me. My car was searched and nothing was found. I was not given a drug test and I didn't refuse one. I was held at the station for 6 hours. Once I was released I was given my paper work and I received a pink paper that says to contact the DMV for a hearing. This paper says it's for people 21 and over and I'm 18 years old. Is it possible for me to win the DMV hearing and possibly get my case dismissed?