What must you check when transporting bicycles on a rear-mounted support system?

You answered correctly because all three points are important for safely transporting bicycles on a rear-mounted support system in Germany. First, you must check the manufacturer’s instructions to ensure that the carrier is suitable for your specific vehicle; this prevents damage and ensures stability. Second, both the carrier and the bicycles must be securely fastened to prevent movement during driving, which could cause accidents or damage. Third, you need to make sure that the carrier and bikes do not cover the vehicle’s lights or license plate, as this would be illegal and reduce visibility for other road users. Following all these rules ensures safe and legally compliant transport of bicycles.