Simulink is a popular tool for modeling cyber-physical systems. As more models are produced in industry, automated quality assurance of models becomes increasingly important. This paper describes an empirical evaluation of four methods for the coverage testing of Simulink models: A) SimuLink Design Verifier (SLDV), a dedicated official tool; B) Template-Based Monte-Carlo (TBMC) method, a random test generation method that utilizes input signal templates; C) SMT- Based Model Checking (SBMC) method that conducts static analysis via encoding models into logic formulas; and D) a hybrid method of B and C. Based on the evaluation results, we carefully designed the hybrid method to complement the features of TBMC and SBMC. In the experiments, we have applied the methods to fourteen models and evaluated their performance. The results show that the hybrid method achieved better results than SLDV for several models.