If you are a 16 year old who stole your mom's car without permission, you don't have a driver's license, and you are with 4 of your friends who also don't have a license.
Maybe you should not be driving. Better yet, maybe you should not have pot in the car.
Better yet, when the cops pull you over don't make furtive movements like you are hiding shit in the car. Especially wise if you are in an area of town known for high crime so the cops won't be inclined to think you are a dirt bag that might warrant being shot.
And when you get your ass hauled out of the car and they get ready to search it(which they are going to do since you gave consent), tell the cops there is pot in the car. That way they won't have to come back and play stupid games with you about why the car smells like pot and who it belongs to.
Considering the above, maybe the cops won't have to call all of the parents and explain to them why their kids are still safe despite the rampant stupidity on the part of the kids. All of the above factors will play into whether the cops decide to play the role of hard ass or the role of a lecturing mentor.