I have my own dashcam. It is forward facing, not driver facing, but it does record audio. So, it records the audio signal I get from my Prepass unit. I usually also verbally say what signal I get out of GP. Haven't had to use it with DOT for any reason, but that is how I CYA myself for weigh station bypass signals. Also, fairly common here in the West for a weigh station to also have an illuminated sign indicating if you have to pull in or get bypassed. My camera records that so it's another way I could CYA if needed. That's what I do.