abidali Hi. The factory fan spins correctly, but it doesn't generate enough airflow to prevent the aluminum from continuing to rise. I replaced the thermal solution with a 1mm-thick aluminum plate and thermal paste on both sides. It's much better than a thermal pad. It still wasn't enough until I replaced the fan. Wait until summer, when ambient temperatures are higher, to see if you start having problems.
Dudu7 head unit reboots by itself
I ordered this fan and will take photos of the internals when I have everything apart.
https://www.amazon.com/dp/B072JK9GX6
8 days later
- Edited
For those that are interested in the internals and what it will look like when replacing the fan in this manner.
Here is mine, 
Arielnac
It looks like the fan pushes air into the Mekede case and vents out the slots.
For both silence and airflow, I'm looking at using a duct and standard 120mm PC case fan.
Does anyone know whether the little 12V fan from the factory is PWM or just on-off?
ManOfScience On and off at full speed. Therefore the little fan is loud as hell.
If you want PWM you need to buy a 12 Volt PWM module.
Yes, I will do a final decision after fully reassembling the dash. Right now the sound of the fan is too loud.
If the larger fan is necessary, I will certainly run a temperature sensor to control the fan speed, with a minimum speed set at inaudible.