I've got a good quote from Andy, 590€ shipped.
Now I've to decide if I'll go for a dash cam or surveillance...
Seeing the photo in your first post I'd go with surveillance.
Unless you got your car parked for a long time, the average power consumption (idle) is between .25~.50 A/h
Which is a lot, if true. Would drain the battery of my dash cam in an hour or two and my car battery in about 3 to 4 days. If you only drive short trips every few days it'll definitely be problematic, unless you get another leisure battery and its electronics.