I can tell you that after the Canadian National Auto Show in Toronto at end of January the promotion they offered was that if you did a credit application at the GM booth at the show you got 1% off whatever lease finance rate was standard for when you order the car. Dont know how long it was good for, but yes you did have to submit an application at the Auto Show.
There is a $500 Ft Worth Auto Show bonus cash available right now to some zipcodes in TX but the bonus cash is NOT available on the Enclave, so my quess is there will be a $500 bonus during/after the Dallas show, but it won't be good an the Enclave.
I would not bet on seeing any rebates at all on the Enclave until next fall when they try to sell all the reamining 08's..
You can't find them on the lots here in the Dallas area, especially the CX cloth model.