The SJCam looks pretty good and comes with a few attachments.
I also watched a youtube clip last night which said the so called fake SJ's are actually from the same company, there only around £15.00
I've got an SJCAM SJ4000 wifi, pretty good cameras and come with all you could need. Not used it as a dash-cam though, only in day time and under water- both of which it performs brilliantly. Got mine from Amazon after reading about the fake ones, I got the cam, two extra batteries and charger, 2 x 32gb micro SD cards and a case to keep it all in for less than £100.