Do rebates usually get renewed?

Sorry if this is considered a double post from my other one:

In your experience, if a manufacturer if offering a rebate on a fairly slow selling car and the rebate expires, does it tend to get renewed? Is it usually at the same, lower or higher value?

Specifically I'm asking about the $1,000 rebate offered by GM on the 2007 Pontiac Vibe.

From what I've seen in the past, there is a good chance that an expired rebate will be renewed, especially if the rebate in the past has helped to move more vehicles. If the rebate has expired, sometimes it seems the manufacturer waits a short amount of time to see if the sales continue on the same level or drop. Then they decide to bring it back. I've also noticed that many manufacturers seem to talk out of both sides of their mouths. By that I mean one day they say that once a current promo like 0% financing is up they will not renew it. Then a few weeks later, you see them bringing it back. This happened a few years ago when automakers like GM said that they were discontinuing 0% financing only to renew it because another automaker kept their going. A lot of time it also depends on what I like to refer to as "peer pressure." Sometimes, when one automaker comes up with a promo, other automakers feel they are forced to join in to keep up and continue to bring customers in the showrooms.( Why have the competition get a "leg up" when you can offer the same thing?) Same goes for some of the promos that ran in the past, especially the 0% offers. In the past when GM said they were discontinuing it after a certain date, they changed their minds when the competition,(Chrysler) decided to keep theirs going. On some cases they might "one up" the competition by improving upon the offer, (such as 0% PLUS cash back.)