A car runs over a man's head as he lies in the road. Only the characters in the car's reactions are shown (they don't see what happened and assume it's a speed bump), but the noise is quite graphic.

Not exactly squashed but one character's head gets severely mutilated by an accident involving a utility pole and another character smashes his head on a desk repeatedly.

There is NO literal head squishing in the movie. Thor's head is seized and threatened to be squished, but THAT IS ALL.

Oberyn Martell's head is crushed by the Mountain.

There's a fair amount of decapitation which leads to heads being kicked and carried around

Does a head getting eaten count as squashed? I'd say yeah, but some my disagree.

Twice throughout the movie a head is squashed, one being possibly the most gory death in the franchise.

Yeah, a bunch of walkers get their heads squished throughout the show, there are so many instances of this happening that I can't think of just one example.

In the first episode of Golden Wind Giorno uses one of his abilities to send the damage from an attack back to his attacker, Leaky Eye Luca. This causes the back of his head to cave in with an imprint of the shovel he was attacking Giorno with.

One gets ripped off, so yea

Heads explode in the game from direct gunfire and other assaults.

One character had his head bashed in by a metal ball, although I don't think there was any gore shown, only blood.

a character gets bashed in the head with a hammer while gardening

A man gets his head slammed into a mirror, then bashed into the sink repeatedly and suffers injuries from it.

several characters are graphically shot in the head

If you follow the Dark Brotherhood questline, there is a head-squashing.

In a very gory scene, a character is murdered by having a big stone spike from the church roof pushed onto him. His head and upper torso pretty much explode.

Two people die by falling, with obvious associated traumatic head injury, but no heads are squashed like by a car or other object smashing into it.

100 peeps all smash their heads - the movie

ded pool of blood around broken face

Someone's head is crushed with an ATM machine.

Several heads /are/ blown off by a gun, though

The main group runs over several corpses on a supply run. It's implied they run over a head but it cuts away and only a sound plays.

Characters could die by getting their heads squashed between a wendigo's hands.

Episode 1. Refering to blood/gore warning.

Rick's head gets Cronched