Brought my truck in Feb '05. My dealer "tried" to tell me I had to wait 6 months before I could pay it off. I called Ford Credit. They said I could pay off the loan as soon as I got the first invoice. You got to send the final payment to a different address when you pay it off so they'll notify the DMV and send you the title. Probably could of put the check in the mail to Ford Credit after I picked up the truck and paid no interest.
Basically, the minimum $8000 24 month loan I took out to qualify for the $1000 rebate cost me exactly $38.07 in interest. Call Ford Credit the number is 800-727-7000. I think dealers must get some sort of kick back from Ford Credit. Imagine how much money Ford Credit must rake in if they can afford to give $1000 to take out a $8000 that you might pay off in 1 month.
I also put a portion of the purchase on the wife's CASH BACK credit card. They only let me put $3000 on the card towards the cost of the truck. Would of put the whole remaining balance on the credit card if they let me.
If you have the cash you can really save a ton on the interest.