A Dash Cam that is actually a Dash Cam?

Does anyone know of a dash cam that is actually a dash cam?

All that I have seen so far appear to stick on to the windscreen, obstructing the view, and as my satnav sits on top of the dashboard, on a mat, giving a clear view from the windscreen I am attempting to find something similar, but with no joy so far.

Some advertisements mention placing behind them the interior mirror, but this still leads to the problem of routing the cable down to the cigarette lighter socket as having it hanging down across the screen rather defeats the object.

cheers

Allan