Air Bag Not Deploy problems of the 2007 Mazda MX5

The airbag warning light came on. I took the car to the dealer, dyer Mazda in vero beach, FL. The dealer told me the airbag may or may not deploy in the event of a crash. They said I needed a passenger weight sensor, a passenger seat track adjuster, and an sas unit. Approximately $2,000 just for the parts. I called the manufacturer, Mazda, and after review, the manufacturer concurred that the airbag may or may not deploy unless these 3 parts were replaced. Mazda agreed to pay for the labor only, $650, but I would be responsible for the $2,000 in parts. My car is in excellent condition, only 11,752 miles on it. There was never any damage to the parts - impact, water or otherwise. Since all 3 parts are required for the airbag to work properly, I feel Mazda should cover the cost of the parts - not just the labor. This is a huge safety issue. Mazda oem parts are only warranted for 12 months or 12000 miles. Since these parts are directly related to the safety of the car, I feel these parts should have a much longer warranty - such as 100,000 miles - like a powertrain warranty. I have researched this issue extensively on the internet - specifically in Mazda owner forums. This is not a new issue for Mazda. They have known about it for years. Since the failure of this part can be responsible for driver death or serious injury, I believe Mazda should be held responsible for their product working properly for more than 12 months or 12,000 miles. Another concern I have is that if the passenger side sensor airbag system can fail, then the driver side system can also fail. If both systems fail, the owner is responsible for over $5,000 in repairs. I would appreciate anything you can do to assist me to encourage Mazda to stand by their safety products and replace them if they fail. Thank you.