Found this online as well:

G&R went to the semis in the Mustung and lost the lift gate in the traps at about 150, it flew probably 50′ in the air and smashed into a hundred pieces when it hit the ground, we went over to see what they were going to do and they went and got a Hertz rent-a-car Must II and put the factory steel and glass liftgate on the racecar….that extra 100lbs. probably cost them that hundreth in the final!