If you need to remove the original audio from dash cam footage and replace it with custom music, this is easily done in DaVinci Resolve. You can use either the free or studio version, as the process is exactly the same.
Dash cam footage is normally saved in very small files, which are usually 1 to 5 minutes long. You don't have to manually edit every individual clip, as you can join them together and remove the audio and replace it in one go in DaVinci Resolve.