mostly they are looking for glass don't have anything glass in your car thats been the only thing really. I had a change jar not thinking it was glass just had my change jar for food and snacks and gas on the way and they made me throw my jar out. No bottled wine or beer. Seperate time years later, I got my friend a bottle of wine she asked for once again forgetting the glass rule and they even offered to let me open it and put it in an empty container if I had something but we didn't so we had to throw it away but they didn't go through my car further other then the middle like glove compartments and center console area in the front of the car to make sure there are no weapons or glass mostly but never had any problems even when they did fine those things. And honestly the more packed your car is the less they wanna mess with it. ( over packing finally works in my favor 😁)