Deer whistles come in pairs, tuned to 2 different frequencies, that stick on the front of a vehicle and are powered by the car moving through the air. There are also units that combine both whistles in the same unit. Designed to deter deer "in the headlights", they are very cost-effective and easy to install. Although there are deer-whistle skeptics, they are very inexpensive with few, if any drawbacks. I have had good luck with them on many different cars over the past few decades. I never hit a deer and can recall many cases where the deer froze, looked at the car, then took off into the woods. I just installed them on my new Model 3, as shown in the photo of the left one. In a future SW update, Perhaps road-kill avoidance could be done instead using the existing pedestrian warning speaker located at right front, facing downwards. It appears straightforward to add two tones at different frequencies, or something more sophisticated, enabled when driving forward, in addition to the current warning noise. Other species-specific deterrents like moose, camel, kangaroos, etc. could be developed and added in future updates.