Has anyone mounted a dash cam in their car?

I have seen a lot of in Europe, but not so many here. I'm interested in having one. I'd like something motion activated, so it records when the car is moving, and also overwrite the oldest video when there is nothing of note to save. Would also like one I can hardwire to the car rather than having to remove it for battery changes.

Does anyone have advice on these?

 

never heard of someone besides police using them. do you have a lot of "youtube" moments?