Hi James
So sorry to hear your bad news but wish you well in future.
My guess with the car having bought my previous Motability car is you buy the car on an “as seen basis” and they give you call asking if your happy with the state of the car as in mechanicals and bodywork and when you say “your happy” that’s it.
With my ex-Motability the car was 3 years old so out of any manufacturers warranty and you have no warranty but of course you know the car and how its been driven and treated and to me is the best warranty.
With my current car it has a 7 year warranty and the manufacturer allows the warranty to be passed on to new owners so in that case you would get warranty but apart from any passed on warranty from the manufacture your on your own.