This is true, but there are still incentives to fake your residency. For example, you only have to pay the Rundfunkbeitrag (17,50 € per month for the public med

This is true, but there are still incentives to fake your residency. For example, you only have to pay the Rundfunkbeitrag (17,50 € per month for the public media) once per household, so students can save money by pretending to live at their parents' place. For car taxes it's usually better to be registered outside of urban areas. The government even changed the law to make faking your residency harder, now you have to register with some form that has to be signed by your landlord.