Marty told Doc Brown his concerns about his memories not matching up with the events of the current timeline. However, as he said this, Marcus Irving took the opportunity to steal the flux capacitor from the second DeLorean time machine, and remove its tires.
Marcus knew that Doc would be able to build another flux capacitor and would be able to replace the tires, and he feared that he would come after him. Thus, he drove his Yugo GX, keeping an eye out for the DeLorean, until 1997, when he decided to use the flux capacitor to complete his Yugo time machine. He then traveled to 2008 to bring future technology back to make himself rich.
- Marcus Irving managed to steal the flux capacitor, which he used to travel forward in time to bring back technology to make himself rich.