Are you referring to me? I was not saying that you or your situation was silly. DrDemento has a long history on this site for several years making similar comments. That's fine, to each their own, but he seems incapable of doing so without directly quoting, even when his post is directly following his own. That practice is what I was calling silly. Not only is it unnecessary, it makes reading these comments and the number of pages much longer than it needs to be.
As far as your test, be sure to have the battery removed. Try to have open airflow around the camera. Placing it on something cool might help as well. Most importantly, be sure to do a FULL format of the car in your computer first. The SD card association recommends using the tool on this site
https://www.sdcard.org/downloads/formatter/Be sure to choose the complete overwrite. Once done, format again in the camera. You may share want to test with a second card if the first test doesn't go well. Overheating is often caused by the card (along with what has been previously mentioned).
Good luck with your test. If it doesn't go well, you might want to try a non-action camera, or at least one that isn't sealed in a waterproof case. Unfortunately, most DSLR and mirrorless cameras will also overheat after prolonged continuous recording, but camcorders tend to do well.
Turn off all the features (GPS, Voice commands, Connections < very important, stabilization < no need if the camera isn't moving), remove the battery, and record in 1080p/30fps. Let us know how it goes.
