Upvote:1
As a mexican citizen crossed multiple times between the US and MX by car, let me share with you, that in my last experience a few months ago, I crossed to MX while my dashcam was turned on, I really did not take any care about that, no officials stopped me, even looked at me. However, I look like mexican, I had put my mexican hat, my car has mexican plates. If your car wears US plates, I think officials take more care about your required permissions than a dashcam turned on.
I think, that situation about dash cam could be more complicated if you are crossing from MX to the US, the officials are more careful.