Car buyers from private mucks up.

I sold my car last week… Today I get a nice text from the buyer: – he was in a workshop and the climate probably doesn’t work (have the climate never used, especially because I had the car only over the winter) – the second key does not work (is even “defected or battery empty” on it) – an outdoor mirror can’t be properly adjusted – he has discovered a fire spot (I said that I never smoked in the car…which is also true (all one on the car) Now he wants me to pay him all the defects, or he wants to return the car (including fuel costs). If I don’t register, everything goes to the lawyer. The buyer has looked at the car over 4 hours GENAÜSTEN and was even in 2 workshops. Purchase contract was one of Autoscout with “exclusion of material defects liability”. Have an appointment with the lawyer tomorrow afternoon. Since the SMS sweetened the evening, I wanted to ask here, what d a can happen at all. Greetings