So, you have an empty beer can in your car. Is that legal? Well, it might be legal, but it's stupid. While the officer might not be able to arrest you for having an empty beer can, it's reasonable suspicion for him to continue your DUI investigation. If he spots a beer can in your car, guess what? He can ask you to step out of the car and take a few tests to make sure it's okay for you to drive. Don't fall for that. Clean your car out, folks.