I've just acquired a like-new 96 Riviera with 65K miles. I've been in love with the body styling since it came out in 95, and wanted to get one while there are many fine examples around. As a mechanical engineer (retired), I always considered the Riviera's engine antiquated, but now in my later years I admit that it does have its good points. The original owner of this car was an absolute nut (like me) in his car care. For instance when rotating the wheels, he always washed the inside of the wheels also. He also waxed the inside of the door and trunk painted panels. The engine compartment was so clean there was no place to get your hands smudged at all. Paid a premium price ($9250), but what I was looking for.
Looking forward keeping up with forum info. There is a bit of info I'm looking for now---availability of aftermarket "heavy-duty", i.e. more firm, suspension components