You will see numbers flash on the screen at various points during the "Dark Past" documentary. The numbers are decoded by assigning them a letter, with "A" being "1" through "Z" being "26".

The first set of numbers translates to "TWISTED", followed by...
Time index 10:30: 13 05 20 01 12 which translates to "METAL".
Time index 13:00: 09 19 which translates to "IS".
Time index 17:15: 03 15 13 09 14 07 which translates to "COMING".
Time index 18:50: 15 14 which translates to "ON".
Time index 26:00: 16 19 20 08 18 05 05 which translates to "PSTHREE".
The complete message is "TWISTED METAL IS COMING ON PSTHREE".