The worst case scenario is that he pleads guilty or his found guilty on the nose, gets put on probation, has to pay fines/costs/do community service/attend classes, and gets an alcohol conviction on his record.
The best case scenario is that he hires a decent criminal
defense attorney in the area who can work out some type of plea agreement
. Two possibilities to explore come to mind (a) have the case handled under a diversion program where, upon successful completion of probation, the case is dismissed or made non-public, or (b) have the case plead to a non-alcohol offense (e.g., disturbing the peace/disorderly
person)...again put on some type of diversion track.
The miracle scenario is that the defense attorney tries filing a motion to dismiss and argues that a minor transporting alcohol in the trunk (for someone else over 21) is not illegal.
Good luck and best wishes!
I hope that you find this information to be helpful and this answer to be ACCEPTable!