I signed up just to post this. I recently purchase a Mobile DVR from Gadspot.
Here's the link: http://www.gadspot.com/p-315-gs3000cdr.aspx
I've only used it for about a week. The quality is pretty good, though I wish the night time video would be better. It looks like what you're looking for. It has GPS mapping and also records your speed. It claims to be 5 megapixels and plays 1080p. I haven't compared it with other brands or models, but I'm quite satisfied with this one.
They have a youtube video for it if you want to check it out:
It's pretty simple to use, I haven't had any problems with it so far.