Slither (1973)
Starring James Caan and Peter Boyle.
This movie is A riot from start to finish...
I have it on vhs but alas no DVD release in sight.
Plot: While searching for a small fortune of embezzled money, an ex-con, a small-time bandleader, his doting wife and a kooky drifter find themselves being followed. Their chase takes them to trailer camps, bingo halls, laundromats and ultimately, a showdown with a group of unconventional bad guys.
imdb link below.
http://imdb.com/title/tt0069282/