Pros: Solidly built, quiet, roomy, extremely comfortable ride. Drives well in snow/winter weather.
Cons: Not enough cup holders. Wheel caps loosen with age. Headliner starting to sag.
I bought my 1991 DeVille a couple of years ago, with 112K on the odometer. I've since put another 22,000 miles on it, and it has been a very reliable car.
Let's get the annoyances out up front: There is only one cup holder, and it is one of those afterthought ones that clips onto the end of the arm rest. Kind of odd for a car that can comfortably seat five adults, but that is more an artifact of Detroit design from that period.
Also, the wheel caps (7" covers for the tire lugs, as this model does not use full-sized hubcaps)have a tendency to become loose with age. I lost one and they are not cheap to replace. The best price I could find on the internet and locally was $50!
Like many GM cars, the headliner (the interior ceiling) is starting to sag. I'll have to get it replaced soon.
Okay, the good stuff: The 4.9 L fuel-injected V8 gets surprisingly good mileage; 24 mpg for everyday driving and 28 mpg on the highway using cruise control set at 60-65 mph.
If you are a competent "backyard mechanic", this car is not too difficult to troubleshoot and work on. A Haynes manual is a good investment. I do all my own maintenance (brakes, oil changes, etc.)
The interior upholstery is soft, smooth leather. It smells and feels like an opulent, leather-appointed, gentleman's smoke room. Road noise is minimal (the quietest car I've ever owned) and the suspension is smooth, easily absorbing bumps and uneven pavement.
The exterior finish has held up well. For most of its life, this car was in Virginia Beach and was not garaged, but the paint and clear coat finish are still brilliant. No rust anywhere. It has since weathered two New England winters, again ungaraged. I take extra care to keep the car clean, so as not to let corrosion get a foot-hold.
This is definitely a car I want to keep as long as possible. It is an excellent car for long road trips, as well as everyday transportation.