Just tossing out some thoughts to kick around here so kick away at them, but please refrain from kicking people as that is counter-productive
One of the 'heat sinks' in flashlights is the mount; in these cases the human hand with the bloodflow providing 'liquid cooling' too
So a dashcam mount could also be used to help dissipate heat, potentially to the surface which the mount attaches to as well provided it is cooler than the cam's internals, yet they all seem to be plastic which doesn't have the properties needed to transfer heat effectively
The lens housing could be finned radially (concentrically) at almost no extra cost since it's already being turned on a lathe or mill, and that could help dissipate the heat of the sensor. Active air cooling is used in some custom lights- simply a 1" (25mm) pancake fan such as computers use which are made for 5VDC. In something the size of a wedge cam such a fan wouldn't appreciable increase the size of the footprint, just the thickness. Not expensive either but would need stronger power supplies
My 24/7 always-running-in-a-hot-van Mobius doesn't have heat-related problems even with it's tiny CPU heat-sink which to my eyes is of questionable value due to it's small radiating surface). Heat CAN be a problem
but if Mobius can do this then there's no valid reason similar systems cannot Ambarella processors run hotter, but is their performance gain worth making better heat management worth having just to use them? Higher bitrate equals higher heat because more processing work is being done. Again is that gain something worth the extra heat-sinking effort it would take to implement? And what of other processors?
In conclusion it seems to me that it wouldn't be too hard or too costly to dissipate more heat if that's necessary without making major changes to form factor although it would probably take the manufacture of a new case design. Yet other than the lens assembly is such extra effort is necessary; has someone actually tested-to-toasting these processors or is everyone just following the chip-makers specs blindly? An automotive interior can be a tough environment but the other electronics in the car and under the hood where is even hotter don't go toast and some of those are working pretty hard too.
tldr: Better heat management is easily possible but is it really needed, and would it be worth the extra cost and effort?
Kick away!
Phil