Ebay is a good place. Look for a camera that records in .H264 as thats the best quality. 1080p is less important but heavily advertised by some sellers but its the encoding type that gives the better quality.
Mine cost me about 60 quid and it is of high quality and comes with gps location, speed, your car details and a host of other information and features. On the one occasion i needed to give some film to the police they were well impressed with the quality.
Ill try and find it and post a link.
---------- Post added 03-09-2014 at 09:51 ----------
Youre welcome mate