Historic documents* found by Logan Lawson of the Pilot Car Registry (www.pilotcarregistry.com) debunks decades of conspiracy theories revolving around what killed GM's 1960s electric car efforts. It's a long story, going to the moon and back...
Beginning in the mid-1960s, General Motors Defense Labs was heavily, and secretly, involved with the development of an electric drive system for NASA that could power the lunar rover on the Apollo 15 moon mission. This particular capability would give astronauts the ability to travel much further from the lunar lander than ever before. Partnering with Boeing later in the process, mainly for use of their test facilities that simulated an accurate lunar atmosphere, General Motors took on the awesome task of developing the drive system that went into the lunar rover chassis.
GM needed to test the drive system over long distances, effectively trying to run the system into the ground in an effort to uncover vulnerabilities. This was, after-all, to be the first "car" on the moon, taking astronauts further than ever before, and the whole world would be watching. It HAD to be right.