Rear tires were leaking air the day I got the car. Funny, the last car I had, a 93 Deville had the same problem. I brought the 2002 back the next day and the dealer gave me a hard time because I didn't have an appointment, but they fixed the car. It still leaks a pound or two a week. I've lived with that for over 4 years, no big deal.
Heated seats inoperative when I got the car. I never bothered with it.
Some type of sensor caused the engine light to go on and off. A $350 job, if I hadn't got the extended warranty.
Will need tires and brakes in the near future, but to be expected.
Car has in the last year or so developed the high speed shimmy others have commented about. New tires and brakes should cure this.
Although soon I expect this car to probably break down with numerous out of warranty items, and cost big dollars to repair, at this point I consider my 2002 Deville the best car I've ever owned. I've only put less than 20K gently driven miles on the car in the 4 years I've owned the car. However, my previous 93 Deville needed numerous repairs in the time I owned it, only driving it around 50K miles in 10 years.
The 2002 was also Cadillac Certified, but that really means nothing. My car was just simply taken care of by the previous owner, and didn't need repairs. When I bought the car, I inspected it much more minutely than I did my 93. My 2002 was almost flawless, compared to the numerous flaws and dings on my 93. Also, I bought from different dealers. My 93 had been an out of state auction purchase, the salesman had told me it was a local trade. The salesman I bought the 2002 from offered to call the local owner for me to talk to. Dealers make the difference. I always felt cheated by the first dealer. With the second, I felt honestly treated.