concatenating mp4 files without re-encoding with ffmpeg

Following https://ottverse.com/3-easy-ways-to-concatenate-mp4-files-using-ffmpeg/ and https://finance.uw.edu/recmgt/resources/list-your-folder-structure-windows

• dir *.mp4 /B > filelist.txt
• In notepad, find/replace VIDEO_ with file VIDEO_
• ffmpeg -f concat -safe 0 -i filelist.txt -c copy mergedVideo.mp4

After that, speeding up the video 10x using Avisynth to open the file in VirtualDub - the two videos below. The second video's last part seems to have some missing segments, probably because the dashcam's power adapter came out of the 12V socket. I've now replaced it with one which I had purchased earlier, which has a better grip. 

The camera-generated timelapse and other info is at this post.