Sale of converted Passat Combi automatic

Hello, I have a few problems with the sale of a disabled just unbuilt passats, year 2/2009 and only 9200km. My father was paralyzed after a truck accident (work accident) and got some subsidies from the BG to his car. Unfortunately he died half a year ago and my mother doesn’t need such a big car and can’t afford it financially anymore. So I try to sell it. My most important question is, what can the The car was converted for 16500€ and there was an additional grant of 7600€. He received the grant because he did not take an electric wheelchair or something like that. It was bought in February 2009 and rebuilt in June. The BG subsidized with the clause that the car must be driven at least 5 (??? am not quite sure) years before my father could sell it. That’s only 2.5 years ago and now the BG demands a return payment. Is that okay? Isn’t this clause “failed” with my father’s death? The funny thing about it is, for the expensive conversion, they don’t seem to want a refund. I think that’s strange! I don’t know where to turn and my mom is clearly overwhelmed. Another question is where to advertise the car best. I’d be grateful for your advice and maybe I’m lucky and it’s interesting. If one of you takes care of the car, I’ll be happy to post the vehicle data and some more photos. Bye and thank you Semmy