This August 27 DETROIT NEWS article describes GM's problem: just-in-time manufacturing. If its suppliers are not y2k compliant, will GM shut down in 2000?
Then there is the matter of 7,000 computer systems in its overall system of production. That is a lot of code to fix.
How many lines of code? The article says 2 billion. I have written to the newspaper for verification. This estimate seems too high. AT&T has "only" 500 million lines. But if it's true, I'm glad I'm not in charge of their repair job.