Cyber-physical systems integrate computational and physical processes and allow for smart applications like smart transportation, smart buildings, and safety systems. While some applications support us in our daily life, others are safety-critical like vehicular active safety systems. Systematic testing of such critical cyber-physical systems is a crucial, but very challenging task that so far has received little research attention. In this paper, we present an investigation on the state-of-the-art and future trends of testing critical cyber-physical systems on the example of active safety systems for vehicles. We conducted four focus groups with Swedish industrial partners as well as systematically studied proceedings of a recent active safety conference. Our results show that while the main testing processes and scenarios are supported, there is a clear need to enable testing of more complex scenarios in realistic settings, as well as increasing the degree of automating therefor to achieve better repeatability and a more effective test resource usage.