The Ultimate Vampire Resource and Directory

In the distant future, Earth is fighting a losing war with an alien race known as the Glorft. In order to save the planet, the human resistance steals a giant robot, Megas (Mechanized Earth Guard Attack System), from the Glorft and modifies it. The idea was to send Megas back to the Battle of the Last Stand, which was the last major offensive fought by humanity against the Glorft. Humanity lost that battle, but the members of the resistance believe that Megas can tip the scales and hand the Glorft a decisive defeat.
Before the plan can be executed, however, an attack by the Glorft forces the human hand to send Megas back in time. The prototype time drive, however, accidentally sends the now-crippled Megas (its head was blown off in the attack) all the way back to the early 20th century. Megas languishes in a New Jersey junkyard until it ends up in the hands of two slackers, Coop and Jamie, around the year 2000. Coop turns Megas into a hot rod project and names it XLR, for extra Large Robot.