What is the maximum speed you are allowed to drive a car with trailer on roads outside of built-up areas?

You answered correctly. In Germany, when driving a car with a trailer outside of built-up areas, the maximum allowed speed is 80 km/h. This rule helps ensure safety, as towing a trailer affects braking distance and vehicle stability. There are exceptions where 100 km/h is allowed, but only with special trailers and under strict technical conditions. Unless these exceptions are met, you must not exceed 80 km/h on such roads when towing a trailer. This helps reduce the risk of losing control, especially at higher speeds. Remember this rule when driving with a trailer outside cities and villages.