I had a dealer-serviced, still under warranty Volvo with 18K miles on the odometer and documented oil consumption of 1 quart per 3000 miles, essentially the same as yours. VCNA initially refused to do anything and told me that oil consumption of one quart per 1000 miles was "normal", which was clearly a baldfaced lie. I got nowhere until I threatened and wrote up a lemon law claim, after which the dealership quickly got the regional rep to agree to a buyback. The operative factor in my (and your) favor is that a used car with a lemon law claim on its record is tainted and virtually unsalable by the dealer, even at auction. In my case, I got a new car in an even-Stephen swap, and the dealer got to resell my old car to an unsuspecting new owner at used market price. All ended well for me and the dealer, but probably not for the second owner who inherited my oil guzzler. Unfortunately, your having had your car independently serviced weakens your bargaining leverage, but a threatened lemon law filing may be your best weapon. Good luck.