I bought my 1995 Riviera with 26,000 on it. It was pretty much trouble free until about 45,000 miles. Between 45,000 and 70,000 miles I spent about $5,000 on repairs. I really love the styling of this car, it's fast, ride is great, and I got 25-27 mpg on the highway. If you really want one, be prepared to spend a lot of money with your mechanic. You'll also need to be meticulous about scheduled maintenance. I sold mine in July of 2003. Fortunately if you're in the market for one, they're very reasonably priced.
Great ride, supercharged engine makes this bigger vehicle take off like a rocket!