Finally, I've got the one missing division of General Motors here -- Buick. This is a 1987 Buick GNX.
I wanted to add the 1980 LeSabre Sedan, but I couldn't find a decent example. Oh, well. As soon as I scan parts of the family album, you'll see one.

A 1967 Buick Riviera! :)

http://www.riekmann.prohosting.com/magazin/buick_story/Buick_Riviera_1967.jpg

And though I've posted this before, here's a 1986 Buick Six-door Station Wagon.

This is a 1958 Buick Limited. Photo taken at an all-G.M. car show in which I displayed my '69 Cadillac Fleetwood.
I was really impressed with this Buick... a very long car (228"), plenty of people and luggage room, and TONS of chrome. I could just sit and stare at this car for hours!

A 1971 Buick LeSabre convertible. . . :)

http://www.avonhill.com/thumbnails/convertible/1971_Buick_LeSabre_conv.jpeg

. . .with the top up! :(

Buick LaCrosse

http://www.cardata.com/2005/Buick_LaCrosse.jpg