Well a car weighs usually around 2000 to 3500 pounds depending on the model of course. Now if i could remember my dynamics from college i could do an exact calculation but my instincts tells me its probably just over half the car weight to get lift. (weight/sqrt(2) maybe)
This question is like asking what kind of deadlift do you have to have in order to flip a tire. The two really aren't that relevant...if you know HOW to flip the tire OR the car. I used little back strength to flip that car, at least not like in a deadlift.
Lots of upper back, explosiveness, and LOTS of technique. Being able to drive INTO the car is more important than standing up with it...just as with the tire. If all you do is deadlift the car up...you are NEVER going to flip it from there.
Here are a couple of pics of me and the one car that I flipped...with poor form.
That looks fun! I can see myself now lol. Best damned party trick I've seen in a while, think it happens on OSU campus a few times a year when they win. Of course it a few of the doing it.