Following on from my successful "name that song" thread, I've got another one - name the movie!
This one is a bit more obscure and I'll be surprised if anyone remembers it.

It was a horror movie from either the 70s or the 80s (I remember it was in colour). I think it was set in America or Canada. No idea of actors or specific timeframe.

My Mum used to rent out VHS movies in the late 80s for my sister and I to watch, and - for some reason - we ended up seeing this one.

The scene that sticks in my mind (and it's quite grisly, even by today's standards): there was a couple driving in a car (from memory LHD, so either America or Canada) following a logging truck up a hill. Something happened and two logs slipped off the truck, slid backwards and into the windscreen of the car behind, basically chopping off their heads and killing them in the process.

That's the only scene I remember and it was quite early in the movie; I think I was probably too traumatised to watch much more! To this day I always allow a realllly long distance when following any logging truck, so it obviously had an impact on me!

If it sounds familiar to anyone, I'd like to know.

Note that this is not so I can show my boys...this is just for my own curiosity as to what it was called.