I would contact Motability about this. They have a fining system for dealers who do daft things, and I would have thought that registering a car on 30th August would be one of them! That being said, we are picking up a new car tomorrow, just 2 weeks before the 74 reg, and it hasn’t been queried. I would have left it until 1st September (which the dealer was happy to do) but we are away that week and want the new car as we are having a person hoist for the first time and having it for our holiday will make life a lot easier for my wife. However, to answer your question, the dealer is wanting to get the car in to their August figures but, as others have said, you are the customer so if you want it on 1st September they should agree to it – and Motability will thank you for it as it will add around £1k more to the residual value at the lease end!