Cool Buick Riviera Concept PicturesGeneral Motors was showed off its futuristic, but Buick announced more than the LaCrosse over in China. Autoblog Chinese brought us pictures of the Buick Riviera Concept when the car was revealed at the end of April, but I think readers will still be interested in this vague-sounding "fuel-efficient" possible hybrid. However, you can watch the video to see what it’s like. Video after the jump!