I installed a Thinkware X700 in my car. It has front and rear cameras and GPS. It was $156 on Amazon in 2022. The rear camera is small and just sticks on the rear glass inside the car. The GPS is nice because it records your speed so you can prove that you weren't speeding or weaving or breaking any other laws. I guess that could be a bad idea in some cases! Years ago, I had a cop follow me through a 25 mph zone for over two miles at 1 am. He was so close that I couldn't see his headlights in my mirror. Nothing happened, but I'm prepared for the next time.