Firstly, we'd advise you to make sure you understand all the laws in each state where your drivers are active. It's obviously possible for your drivers to adhere to different laws while driving in different states – for example, moving their dash cams around, or switching audio recording on and off. However, it'll be much less complicated if you just aim to adhere to as many of the relevant laws as possible all the time. Mount your dash cams on your vehicles' dashboards, disable audio recording (or ensure your drivers get consent to record audio from their passengers all the time), and avoid recording on private property at all times. That way, fewer mistakes are going to be made.