Best thing to do is phone up and begin the process.
Make sure they understand all your problems that relate to getting in and out of a car and what features of a car you will require as a “need” not as a “want wish”.
Such as if you cannot reach above your shoulders/head then you would “need” a car with a power lift tailgate.
If you have arthritis and you cant bend knees/wrists/elbows very well then you would need an automatic transmission/electric seat movement.
If you have Raynauds and you cant stand touching cold surfaces then a heated steering wheel would be a need.