Excellent questions heavyheart, you have a tough problem to deal with. If you are in a wheelchair I don't know how you can drive, you may find it tough to get help buying a car. I think your best starting place is to look thoroughly through the government website disability.gov. It is very extensive and is kept quite up-to-date with lots of information about services and resources for the disabled. They have an entire section on transportation, so perhaps if they can't help you get a car they would be able to help you find a service in your area. To get some tips about using and navigating that site you could also check out a review of disability.gov.