in the first run it looks like he lifted a few times. His wheels bounced off the ground 3 times. If you stay in it, that wouldnt happen.
thats why the second run it just hangs the wheels. He stayed in it. In the past he put the car on the bumper and when it came down, smashed in his oil pan, broke his k member and a bunch of other shit. Im sure he was trying to prevent that from happening again.