If you pay cash, you can get cash incentive bonus, from Toyota, over 1000 (I think it is 2500).
Dealers don't make much selling a brand new car to you. The mark up is at most 7%, but dealer has to rent the place, pay staffs. They make money servicing your car.
If you can pool together ten persons buying the same car, you can walk in and ask for a FLEET of cars, you can get at least ten percent discount. But can you find ten persons looking for the same car?
If there is Toyota sales person who is also CFC member, maybe that person can help you. But to reduce 1000, I doubt it. The dealer is offering all service for free. Are you willing to work for free?
If your bottom line is 21000 (22000 - 1000), and 0 % finance, there are other options. I think 0 % finance will disappear quickly. When Hyundai Elantra was selected best car, Hyundai stops offering 0 % finance. That is marketing and pricing. Corolla is a great car,but if it is outside your budget, go for another car.