In a motor vehicle, a display device has a display area displaying an image projected by an optical device by way of a reflection area as a virtual image. The optical device has at least one reflector and an actuator which moves the reflector. The actuator includes a shape memory material, which is designed to be deformed by a temperature-dependent phase transition and thereby move the reflector. By the provision of a thermal shape memory actuator that functions without an electric current, the optical path can be changed, so that overheating of internal temperature-sensitive components of the display device can be prevented in a way that is particularly inexpensive and efficient in terms of installation space and it is also possible to dispense with electronic sensing, evaluation and activation entirely.