Costco had pre Christmas sale on Cobra dual channels with Bluetooth so I bought it for our sedan.
I had other cameras before and when cheap were annoying, I found you need higher -resolution if you want to read licence plates. That might not be very crucial in most of the incidents, but can become important sometimes.
Bluetooth gives the camera my location from android and that is very helpful, while Cobra iRadar app is giving you some more option and actually displays routing the way I like it without telling you where to turn for no reason.
I only wish the camera had a screen bigger than 2" as it could also be used as a backup camera.
Lot of choices on the market, but again, don't go cheap on it as it will become more of nuisance than a tool.
BTW I have very good 360 factory cameras on my Ford truck for parking, but so far no way to hack into the system for traffic recording.