I often have a cam on my dashboard top which gets a lot of direct sun and extremely hot. I've measured the temperature in the shaded parts of my car at 50'C so on the dashboard top in direct sun would be considerably more.
This summer a JooVuu X spent most of the time there and during driving it didn't seem affected in any way at all. No problems starting, recording, shutting down. No overheat-related stoppages. No focus shift. Cam still works fine after a summer of direct exposure to sun (it's been an above average summer here).
It wasn't used while parked, although some journeys would undoubtedly have begun with the dash-top and X-cam very hot from having baked in the sun for hours before making a journey.
True, but the warmer electronics run, the sooner they fail. They don't have to be hot to the touch for this to come into play.
On the other hand you don't want to obsess about temperature so much that you spend more time and money preventing a failure than it would cost to replace the failed item. And have an oversized, ugly setup to boot.
Edit> That wasn't a comment about the OP's setup. I'm still amazed you can get a fan that small.