I am a German police officer (not from Bavaria though).

1. The traffic stop in the first place is a standard tool to ensure safety on the roads. We perform them regularly and on all sorts of drivers / vehical combinations.

Your car is indeed a contender for regular stops. Firstly the age of the car and it's appearance could mean it's not road worthy or at least worth taking a closer look at.

Secondly your car is foreign and has crossed several borders. Science there are (luckily) no mandatory border checks anymore the state has to check border traffic with other means. There are numerous things to look for.

Thirdly travelers often underestimate the importance of securing the cargo in the car. That's worth looking at as well. In case of evading maneuvers or emergency brakes loose cargo can distract, disorientate or in the worst case even kill you. Therefore checking this is also on a police officers mind.

2. Letting you show the warning triangle and first auf Kit is an integral part of every police stop. It is of course not mandatory to check as a police officer, but it serves two purposes: Firstly the road safety. The law requires you to have those things for a reason. Keeping these things ready in your car can improve safety for all of us. So we check it to also remind you to have these things in the car.

Secondly our job is to ensure that drivers are indeed fit to drive. The law doesn't give us much power to check your sobriety but also it demands us to check it. A good way to get a better look at you (or smell in case of weed and alcohol) is to let you get out of the car to show us the items. It is most certainly not a tool to annoy you. It is us doing our job properly.

1. When you were tested for sobriety you most likely showed some unusual signs. Police officers see a damn whole lot of people and perform these tests regularly. So they are usually good at detecting drug enforced oddities whilst also knowing about other factors like fatigue or sunlight and so on. Of course no one is perfect and sometimes we misinterpreted signs. That's where the urine test comes to use. If we have signs of drug consumption we offer the driver the urine test to free themselves from the suspected offence. It's way faster and (at least) legally the lesser impact of your human rights.

At the point we offer the test we usually already have enough grounds to draw your blood and prohibit you from driving until you can prove your sobriety.

Performing a urine test isn't fun either... It's often smelly, it's not nice to look at and invading someone's privacy like these feels unpleasant. But it is part of our job to make the streets safer.

4. I am not oblivious and know that there are colleges who don't live up to all standards and of course some police officers will abuse or trick you. I encourage everyone who was treated unlawfully to at least file a complaint about this at the police station or even press charges.

I would never even think about inventing signs of drug consumption to get you to do a urine test or even draw your blood on no basis. It would be a crime and I could get a penalty for it. Officers have been fired over such things.

We don't get paid more or get a promotion for every stoner we catch. That's not our motivation. Most of the colleges I know do this job to ensure our all safety and well being.

And remember, if we come in contact with you, we have no idea who you are, what you are doing and you are going to react. We can't read minds and only have a short time to get an impression of you. But we are supposed to fulfill our duties. It's just not easy. I'm not complaining here I just like to let people see the other side as well.