Hi shaun
I had an auto-chair hoist fitted in my last car, KIA Carens, it was a seven seat car but seats six and seven were never used as that space was occupied by my scooter.
The hoist was bolted to one of the unused seats seat belt anchorages with the seatbelt gubbins tied up out of the way so it could be restored later when the car was returned. Although the hoist itself is the same for any given model the bracket that secures the hoist to the car I would guess is made to fit the model of car as I can’t imagine that one type of bracket would fit all cars.
One other thing to keep in mind as you haven’t said if your car is yours or Motability’s, if its the later then you will need to inform them of your modification.