PUBG's vehicle physics are notoriously wonky, particularly when it comes to collisions. Every so often cars will hit some piece of geometry invisible to the human eye, or just miscalculate the force of impact, and send the vehicle flying.
The video begins with Hawkeyefreak21 pulling their Dacia into the compound of buildings in which their teammate is taking cover. Just as they park, their teammate gets knocked down by a sniper shot. They exit their car to help the bleeding teammate.
As Hawkeyefreak21 revives their teammate, they hear another car approaching in the distance. They leave their teammate to heal and exit cover to spray bullets at the incoming Dacia with two enemies inside, but all at once things go off the rails.
Rather than crest the hill smoothly, the enemy Dacia sails over the ridge, right by Hawkeyefreak21's head, then skids around their parked Dacia to tap lightly against one of the buildings, which launches the car into the air instantly, setting it spinning in the sky before it explodes and kills both occupants in a ball of fire.