In reference to the previous owners who have brought up the fact that their Seville's seem to take a lot of oil. I do have the similar problem, but not to quite that extent. At first I noticed the car did seem to be taking a lot of oil, later to find out due mostly to my driving habits. Since the car responds when you hit the gas so well, I tend to be pretty heavy on the accelerator until I get up to speed. Who doesn't enjoy doing that at times? This rapid acceleration attributed to the burning of more oil in my case. I discovered that when I experimented being easier on the accelerator, which did have a perceivable effect on how much oil I had left at the next change. Yes, the car still takes oil, but it is a 275HP V8 mind you. I don't know of a lot of engines that size and bigger that don't. Especially my last car. Which had a 307V8, and took slightly more oil. So I would say that if this car has any downfalls at all, it would be the servicing expenses. But it's not big enough of a problem (in my case at least) for me to be bitter toward the car. I'm still very attached to it and would definitely buy it all over again.
I love the car. It's comfortable, roomy, quiet, responsive, classy, and has never given me any trouble. The whole oil thing is outweighed by the other attributes of the car to me.
I Love the car as well. I have 79,000 miles and experience the loss of oil as well, but have found if I keep the oil changes at every 3000 miles with 10W/30, I am only down half a quart which I don't think is too bad when there is still 6.5 quarts left.
I changed the front brakes and rotors at 48,000 (rotors had warped causing some vibration).
Changed the engine coolant at 60,000 miles.
I use Michelin MXV4 Plus XSE 100H 235/60/16 tires. I am on my second set and have been very happy with the wear and performance from this tire on this car.
The only problem with the car has been the deterioration of the felt inside the rear seat fold down arm rest and some slightly sweeky bushings in the front end suspension.