Help me with a MIP/driving violation case

I live in California. Yesterday, I was driving with 3 other friends, when a cop pulled me over, he never said what he pulled me over for. Since my provisional liscnese was still in force (im 16) he made me and everyone else get out. He looked in the back and found 8 unopened beers which belonged to one of my friends. We called our parents to pick us up. Even though the alcohol wasn't mine, and I wasnt intoxicated, they charged me with a MIP but no one else got any charges, even though the person who the alcohol belonged to also got caught with an illegal knife that he bought for fun. I got charged for a modified exhaust, CVC 12814.6 for violating the provisional liscense (it was 2 am.) and i also got a MIP. I was wondering what kind of penalties and or fines I am looking at, and the best way to argue this case.

There is no argument. As the operator of a motor vehicle, you are responsible for the passengers and content of said vehicle. It is hard to say what the fine amount will be but you can be guaranteed your driving priveliges are going to be revoked till you are 18. You and your parents should seriously consider talking to an attorney soon.