I've been using a Mobius camera in my daily driver for the last two years. I've installed it behind the rear view mirror in a fit a forgot manor. It's been excellent to date.
I've not got around to installing one in the Morgan as I can't think of a suitable discrete fit and forget solution....
This is one, it's about the size of a small matchbox:
http://www.carcamerashop.co.uk/mobius-action-camera-dash-cam-version.html