Can anyone tell me...

I seem to remember watching this when I was about 6 (I'm 35 now -things were different then, I remember renting Texas chainsaw in the same year from ritz video, happy days) but am nature if this is the right film. I remember it being very dark and quite disturbing. Had a few sleepless nights to be sure. Only science I can remember was one in which a guy is left in a jeep (I think) whilst his friend or brother goes off to sort some business and when they return his throat's been cut. Am I thinking of the right film? I know it's a moot point but it would satisfy my curiosity. Still makes me shudder thinking about it. Thanks in advance. Ps if it is the same film, does any one know where I can get a copy.? A couple of scenes in this,together with leather face swinging his chainsaw at he end of 'Texas' and Lewis Teagues 'alligator' helped shaped my childhood, for better or worse. Ta :)