Im assuming that the 8000k oil change wasn't only and oil change it was probably a Maintenace #2 which should be a tire rotation also. At the dealer your not only getting an "oil change" you are getting a full inspection of your car (qc550 Check). If you plan on keeping the car for a while you will want the dealer to know you as a regular customer in the case of if you need work done outside of warranty, IE after waranty adjustments or ford participation. Just my take on it. You are buying the car for $20k or in that range, why cheap out $10 and put stuff on the car that could potentially harm the car. But I do believe that if you space out all of your services by 8000k you should be doing a tire rotation evey service to make sure your tires wear evenly,,, cause you know how foci love to eat tires.
p.s The Ford Dealer should realy be filling you washer fluid at every service.
p.s The Ford Dealer should realy be filling you washer fluid at every service.