Dash Cam advice

Remus

i'm thinking of getting a Dash Cam.  I don't want to spend a fortune though I would consider an expensive model if it seemed the right one for the job.  It would need to always be able to play back the previous ten minutes and to keep running after an incident.  Good resolution to read number plates (on play back) is essential.  Colour and night vision would also be nice.  As a complete novice I don't know what capabilities dash cams have, or can have, so there are probably many aspects that I haven't even considered.

Any advice would be appreciated.