God's muscle car is made entirely of flaming rings of eyes that shoot blinding light in all directions. The human mind fails to conceive a ride more awesome than that, so for now your answer is "BONGHITS"

Just a guess but the person probably modded their rear suspension and, in the process, made some mighty mistakes. Or a professional did it and fucked up pretty bad.

It looks like the forward U-Joint failed on the drive shaft, or the font of the shaft near the transmission wasn't bolted together rightly enough. On an old drive shaft like that, you usually have one end going from the transmission, to a U-joint to the middle of the shaft, to another U-Joint to the end that's inserted into the rear end differential. So if the joint at the rear end side fails, and the drive shaft hits the road, not a big deal, the shaft drags on the road, lots of sparks and your car slows to a stop. If the front one fails and the shaft drops onto the road while you're moving the shaft will basically pole-vault your rear end out of the back of your car. That's what it LOOKS like happened anyway.