I read through my car manual alot to better understand all of my car's features. On page 16 of the 04.5 S40 it states that the seatbelt reminder light will remain on until the driver and passenger both buckle their seatbelt. An audible tone will also be heard. MY CAR DOESN'T DO THAT!! The Volvo dealership in Richardson, Texas says that all the S40's do the same thing and there is nothing wrong with my car. Please check to see if your car does this and let me know.