If you mean something into which a wheelchair can be driven, they don't come smaller than Citroen Berlingo size. I haven't seen anything as small as a Nemo with a wheelchair ramp. Alternatively, if you mean a car where he will sit in the passenger seat with the wheelchair loaded separately, then the best choice is a Honda Jazz that has fold up rear seats so the wheelchair can be stores in the centre of the car. For Wheelchair Accessible Vehicles (WAVs) try www.brotherbood.com/