We're waiting now to see who blinks first. If Delphi shuts down it brings GM to its knees because GM has no secondary sources to fill the parts pipeline it needs to keep going.
You are probably talking a $10,000 per vehicle profit on a full-size Chevy Tahoe, $15,000 on the larger Chevy Suburban and $25,000 on the luxury Cadillac Escalade SUV. That's real money and a real contributor to GM losing money in the quarter.
It's what most savvy Fortune 500 chairmen would do. Everyone expected GM would look bad, and (GM Chairman Rick) Wagoner figured it couldn't look any worse so he pulled ahead bad news for 2006 into 2005.