Dealer told me clearly they get £750 for a minimum sale and not related to the new car payment, he also told me most manufactures give a discount to the dealers if a target number of sales, this is why some are willing to give a discount near the end of a month. So if your trying to get a car from stock, always ring up 3 yo 4 days before the end of the month if they are short on quota they will sell it to you
this is only from franchised main dealers,
brands such as Mercedes, Renault etc that have a mixture of main group dealers in the uk(owned by the car manufacturer themselves) won’t give you much at all even if it’s near the end of the month, but they will sell you a in stock car as the salesman will get the same bonus from the sale as he would for retail.