Land the car face down on its snout hitting a curved surface - a half pipe or something like that.
When landing on the snout, the car would start dancing around and get stuck. It is not possible to move the car out of this position.
I'm not shure if the car is slightly merged with the terrain, but no parts of it seems to have intersected - It looks like the front is magnetically attached to the ground.
This might be a problem related to the terrain intersection, but I thought I'd mention it anyways.
PC specs seems irrelevant for this bug.
I loved Rollcage and Grip seems very promissing! Keep it up!