The GM effect

Durable good inventories falling is usually a good sign of pending production, and after five years of the Bush economy, it's about time. But I have a question for those on the more economic side of things. Joe Richter writes:

Stocks of unsold vehicles at General Motors Corp., the world's largest automaker, dropped to a 48-day supply on July 1 from 73 days a month earlier, when the Detroit-based company started an employee-discount program, according to trade publication Automotive News. A 60-day supply is considered normal.

Which is good, in that automobile manufacturing will be ramped up, which will increase need for supplies, etc. But the special incentive plan is over. GM made little money on the deal and now will have to spend more money on manufacturing.

So overall, this would be a net negative for GM, right? And the net effect on the economy will be a small boomlet until GM gets back to too many cars and no one to buy them. So in a few months all the industrial growth will come to a halt as the status quo is reached once again.

Is that too simplistic, or the general effect of the GM discount plan?