I echo what other’s have said here and the price of your car will not defer much from a franchise dealer forecourt.
I bought my Golf TSi from Motability for reason I won’t go in to here and found one at my local dealer for more or less the same price and remember, you can haggle with a dealer but you can’t with Motability.
Only advantage in my case was the car was adapted for my disability and like 72 said, you know the car and its history right down to how it was driven while a dealers car might of have the guts thrashed out of it.