New way of doing things now if you choose Best to set up a motorbility online account imo that way there will be no need to take the award letter to the dealer plus there are many other benefits in doing so You will be able to access/follow the whole process from this account Take a look at this link https://www.motability.co.uk/how-it-works/order/
This is what I did and it was very easy. Only small word of warning is that if you set it up at the weekend it may not validate your entitlement until next working day.