Joy,

Consider getting a hand control bar for the throttle and brake of your car.
Several people I know who are in wheelchairs and even a few who are not use
this type of vehicle adaptation including my best friend and ex-roommate who
has spina bifida.

This same friend has a wheelchair carrier you might be interested in.
Ican't remember the brand name but can check for you.  Essentially what it
does is place a bar under the seat of his chair to fold it up and lift into
the carrier.

Dave