Dashcam with decent reversing camera functionality?

[itm]

I'm looking for a mid-price (<£120 ) dashcam which has a rear cam that works well as a reversing camera. It'll be fitted to a Honda S2000. I don't think a mirror-mounted cam would work, as there's virtually no space between the top of the rear view mirror and the roof lining.
Can anyone recommend something decent (in the UK)?

 

[jokiin]

you can only get those cheap no name clip on mirrors that have this functionality