Doors that open wide are a major plus here. Bring along the person that might normally be helping you put the equipment in the trunk or hatch to see how they manage with it. Once in the car, see how the controls are placed and whether they are well designed and accessible. Check the gauges and see if they are clear, readable, and not confusing. Adjust the seats for comfort.
Power seats are often a desirable option, as there are more variations that can be tried.
I ve found with the AVN in my hips that I often have to change seating angles or settings while on a trip to alter position and weight distribution. An important thing to do is to go back to the dealer at night and sit in the car. Check if the night time instrument and control illumination is adequate, and that the controls can be used without taking your eyes off the business of driving to find them. Also ask the dealer whether they can install hand controls if they are needed, or if they use a reliable shop to do the conversion. A very important point to explore is on the subject of airbags.