1970s Action/Crime Movie with Shootouts, Lots of Cars, and a Guy with a Rifle Gets Crushed By His Own Car

I remember seeing an action sequence from movie that appeared to be from the 70s that involved lots of criminals prepared for a shootout.  There was a guy with a rifle under his own car (using it as "cover") on the highway or freeway and was firing long-distance shots at other cars, but opposing people shot his tires and crushed him, spewing blood out of his mouth. 

Does anyone remember this cool movie? Thanks very much.