I'm assuming you are talking about the "belt-minder" that goes off every 15 seconds or so (as opposed to the initial chime that goes off if you don't put your seatbelt on before starting the car - I don't think that can be disabled). The way to disable "belt-minder" used to be in the manual (don't know if it still is or not). The reason it should be in the manual is because it's not the law to have a seat belt chime. It's the law to provide seat belts and other safety equipment.
There is still something called personal responsibility in the world. If you want to choose not to wear your seatbelt, you can, and you run the risk of being fined.
Plus, there is always the chance that someone lives on a long private road and doesn't want to wear a seatbelt...
Edit: Try HERE
- post #4