Riviera

via Dean's Garage

GM Styling sketches from the Mitchell Era

Olds Toronado

Buick Riviera

Cadillac Eldorado

I've seen a heck of a lot of styling sketches in my life, but these really knocked my socks off.  Not only are they eye catching designs from Bill Mitchell's crisp "London Tailored" period, but the use of line weight, shading, and forced perspective is just masterful.