my best advice on this is to order mid way through the last month of a quater with all dealers, as this tends to be when they know they need more orders in to up their quota that even in these times gives them a bigger discount from manufacture.
You always have to remember dealers get a extra percentage off all cars if they sell so many in a quater the folling quater which could mean a lot of profit for them, and if 10 motability orders tip them over that number they will roll out the red carpet, offer discounts etc.