I am a Rideshare driver and big in to dashcams. The best bang for the buck is the Coxpal A11T. About $160 on Amazon with all the features you will need. WiFi to send video to your phone or tablet. 3 channels – front, rear and cabin – easy clean install. Their tech support is great and responsive. Get the hardwire kit.
If you have some more budget look on Amazon for Vantrue. I actually have a NIB Vantrue 4 channel demo unit I could sell you cheap.
Stay away from the $40 specials. You will hate them.