Accessory sales spiffs

[volvopm]

New to the forum and enjoying it, heres the questions, i have so many ideas on spiffs to the salesmen for adding accessories at the time of purchase,my stumbling block is getting the sales management on board because they do not want to accesorize anything unless they (sales dept) makes money, i.e. if you purchase a new car with mudflaps on it, it cost them(the customer) 299, but if they buy them after they drive off the parking lot and return, it only cost them(the customer) $165, there is no consistency throughout the dealership, any suggestions on keeping the management supportive of the sales staff?