A neighbor of my grandparents bought one of the first Rivieras. The early Rivs came with the Buick 401 nailhead, Don Garlits built a couple of dragsters with that engine.
My 2nd car was a ‘63 Buick Riviera. I bought it for $300. The PO had sideswiped a guardrail and pretty well wiped out the driver side.
Man what a highway cruiser that thing was! And the coolest thing was the center console - you could hide 12 cans of beer in it simply by pulling the ashtray out and dropping the cans in. Getting them out was a bit trickier.