Keep track of the documentation with one of the best dashcam kits on the market.
You constantly film both what happens in front of and behind the car - in a fantastic high quality.
If the camera is connected to a fixed supply in the car or a magic power box, then it can detect accidents and movements around the car when it is parked. If it is also connected to the Internet via LTE box with Sim card, it can send you a message in case the car is hit in parked mode.
The car cameras from Blackvue are of the best quality available in the market.