[Stefan]

Are there any tech descriptions about the solar roof?
How many watt will it produce in good sunny condition?

Are there any levels of 12V batt power, before the inside airflow will start?
Will this airflow stop, if the 12V batt power drops below a certain threshold?

I will install a small cooling device, which only should start while the stock airflow is running....

 

[Harleyguy]

I know that the Solar Panel has 20 cells each capable of producing .05 volts which gives a output of 10.5 Volts total .If you check in the fuse box I think fuse 27 is for the solar roof more then likely you should be able to hook up a Multi meter and park the car in the sun and check the AMP output of the roof . Never tried it myself I will look for more info for you .
The car was designed to turn on the fan motor when you selected auto start in options I've seen that work on some cars and not on others . I would think the system was designed to maintain 12 volt power while the fan was running .

 

[Stefan]

I found a really small AC.
It is used in the top cover of a 12v car cooling box.
I let it run for 2 days now... without the box, to check whether it is able run for hours without burning down my car
Attached to the box, it sets the inside temperature of the box to 8*C, having an outside temp of about 24*C

If my car would only go 3*C down, it would be worth the work....
I'd think, I need some tubes and such stuff, but it might be less than 100€ in parts.

I need to check the power consumption during operation and compare it to the figures, you will provide and I will get from fuse 27.

Thanks Harleyguy, I appreciate this.