mad man mars

[violntshags]

 I thought the movie was called "mad man mars", but heres what i remember. there are some campers in the middle of the woods, and one person starts telling the story about a killer called mad man mars. So ofcourse he comes around and starts picking people off one by one. One scene he kills someone by jumping on the hood of a car while they were looking at the engine and it cuts there head off. I think it from the late 70's early 80's. thanks to anyone who can help

[Psycho Circus]

That would be "Madman" (1982)  

http://www.imdb.com/title/tt0082696/

http://www.youtube.com/watch?v=ME5A98R6BiI

[violntshags]

awesome, i shoulda known. thanks

[akiratubo]

One scene he kills someone by jumping on the hood of a car while they were looking at the engine and it cuts there head off.

The move you are looking for is definitely Madman, but that exact same scene also occurs in a movie called Home Sweet Home, in case you're interested.