It depends very much on the way the car is set up for the deadlift and the weight distribution of the vehicle in question.
In most cars the heaviest bit of the car is directly over the front wheels which is also the pivot point for the deadlift (assuming you are lifting from the rear and thus you don't actually need to "lift" the engine.
In strongman competitions it's common to have the car on a frame where the back wheels are supported about halfway along a lever with the pivot point under the middle of the car and the lifting bar is at the other end of the lever.
In this case you are lifting roughly 50% of whatever weight is through the rear wheels, normally from a partial DL position.
So while it looks bad ass it's not actually as hard as it looks
Which is why Tom was able to lift the car for reps at the last comp he went it