100% I have one in all our vehicles and now looking to have rear facing too, and have them run on a battery so they record 24x7 (without killing the car - just experimenting at the moment quite how large that battery needs to be!).
Some time back I had been meaning to put one in the wife's car for months, and kept putting it off, some dickhead crashed into us and while saying it was his fault initially, then completely made up all the details about the accident. Ended up going to court, 50/50 and associated insurance bump, and 2 years driving around in a crashed car, because our word against his. With a dashcam it would have settled immediately.
She's been crashed into 2x since, and while I couldn't be sure those crashers would make it up if they knew there was no footage, the footage being present means there were no issues at all getting it sorted.
I also caught a really serious crash on the opposite carriageway a while back. It was clear the crasher had not paid any attention to the road conditions for a considerable amount of time, and was able to provide the footage to the rozzers.
Reason to have them on 24x7 now is that many £100s of damage has been caused to our vehicles over the years as they are parked on the road. The default reaction these days is clearly to just do one if you bump another car and leave the owner with several hundred quid or more to find.
I don't like it tbh, I'm naturally quite privacy-invasion adverse, but it seems if you don't have one, people will just lie at the insurance companies, who also then lie.
