Miranda rights not read and no search warrant for vehicle

I am 17 years old in New Jersey, I was stopped with marijuana in my car (less than an ounce) and my friend, who is 18 was in the passenger seat. There were multiple cops on the scene, and none of them seemed very experienced. I do not recall ever giving the police permission to search my vehicle. I can't repe if they even asked to search it or not, they just did it. As the car was being search, my friend and I sat on the curb in handcuffs. The cop started to read me my Miranda Rights... Half way through he stops and says "wait, you're 17" and then walks about 5 yards to my friend (18 yrs old) and finishes the Miranda rights where he left off. Is there significant mistakes the police made that could make a difference in court? I do not know much about the law, but I feel like the mistakes the police made could benefit my friend more, since he is 18 and being charged as an adult. Thank you.