The introduction of Head-Up-Displays (HUDs) have opened up avenues for a whole range of novel AR applications. However, until these applications become available for the mass market a number of problems need to be tackled. For example, the field of view (FoV) of current HUDs is extremely limited, and real world tracking and 3D reconstruction are still not precise enough to show driving information embedded into wide areas of complex traffic environment. It is not possible to show true AR-visualizations in the display areas provided by the current FoVs. In this paper, we investigate how an AR-like visualization approach in current HUDs (with a limited FoV) can support drivers in foreseeing the future road course. This visualisation uses the already established concept of an electronic horizon. By complying with automotive standards, our application can be easily adapted for series production. With this visualisation we performed a user study, investigating the effect on drivers' gaze behaviour. For this reason the test subjects were equipped with an eye tracking system. The results showed a decrease in both, the number of gazes as well as total glance time on the head unit and the instrument cluster. We also investigated the test subjects' braking behaviour around sharp bends of the road which showed an overall improvement when the visualisation was enabled. Furthermore it showed an increase of the mean glance duration in the area of the HUD. Note that the eye tracking system is not capable of distinguishing between glances at the visualisation in the HUD and the users' glance at objects behind the visualisation - overlapping with the HUD. This would require tracking the test persons' depth of focus. The study showed that developers need to be concerned about not displaying excessively in the HUD, so as not to distract drivers. It furthermore showed that AR-like visualizations have the potential to decrease the time the driver is not looking at the road creating a safer driving experience.