Family car – child severely disabled – discount?

Hello experts, we are still looking for the “egging wool milk truck”. Situation: Parents, three children (11, 7 and 5). A child has now received a severe disability of 70 percent. Currently still an A-Class A169 (built in 2009). Enough from the back of the square, because child seats are integrated into the outside seats ex factory. Elder then has to stop in the middle. Driving profile: Every year approx. 13,000 km, of which 75 percent city and city environment With a “ordinary” Car” would probably come more with excursion trips and short trips. Many short trips (to school, doctor, therapist, swimming course, shopping) that take place with May four people in the car. Five we are rarely on the road. New cars should be. Budget would be 35,000 euros, whereby the question is which car manufacturers offer a discount in case of severe disability of the KINDES. Automatic (fg. the wife) must be, 7-seater (if a friend has to be taken on short distances times) ) It should not be a “ship” because a lot is being driven around in car parks, on supermarket parking places and downtown. The A-Class could be given in payment (premium for change of car manufacturer?) whereby the box already has a repaired sheet metal damage and a paid out very small hail damage. In addition, the automatic (sensor defect) last year for 700 euros has been repaired by a specialist workshop (of course not Mercedes). n Thanks for all the tips.