First, my apologise in advance, since I may have not used the correct terms in English to express myself in the thread.
I also see it like you both. It must be an illegal thing to ask someone for a private diagnoses when they don’t have the competence to have this information. Neither SS in my country details on official papers I received anything else but the strictly needed information.
Seemly, the guy who is selling us the car offered a possible explanation. They seemly need to know if my disease is physical or phycological because in case of the latter, they need to know the level of gravity so they can deduce if I’m a subject who can face to a debit with guarantee for them.
But, as I already explained in my thread introduction, I already offered them more than enough information when I gave them my SS medical resolution where it states that I don’t depend on another person to cope with my daily routines and the fact that I could do other jobs. Thus, if I’m allowed to drive a car, thing I do it quite well by the way lol, I must not be very bad after all.

Anyway, the seller looked a solution after the conversation I had with him yesterday. The finance company was a foreign company so there might be the problem.The seller changed it to a national company and they approved my papers. So, problem solved.

Thanks both for your insight.