Nissan has to put the stickers on because of federal law. Under authoritiy and direction of the National Traffic and Motor Vehicle Safety Act, 49 U.S.C. 30101 et seq. (Safety Act), the National Highway Traffic Safety Administration (NHTSA) established federal regulations that mandate certain warnings on vehicles equipped with airbags. Under Federal Motor Vehicle Safety Standard 208 S4.5.1 each manufac turer must install airbag warning labels to the sun visors of all vehicles sold in the United States. The size, content, wording, diagrams, and even permanence of mounting are all specified in the standard.
As for removal, manufacturers, dealers and service stations are prohibited by the Safety Act from "rendering inoperative" "any element of a device or element of design installed on or in a motor vehicle or motor vehicle equipment in compliance with an applicable motor vehicle safety standard..." See 49 U.S.C. 30122(b). This includes not removing mandated warning stickers. This prohibition does not extend, however, to private owners. So at least under federal law, there's no problem with owner's removing whatever stickers they want to - there are exceptions to this for emissions related stuff - but that's an EPA issue, not NHTSA.
As for products liability or lawsuits from a vehicle you sold, not too much to worry about there. Nobody on this board (unless their Ted Turner) makes enough money to interest most products liability lawyers. Instead, most will go after manufac turers for not making the stickers "permanent" enough. Afterall, why sue some little guy over his house (which won't play well to a jury), when you can go after a multi-billion dollar industry even on a flimsy case. Chances are that the manufacturer may settle just to make the parasites, 'er make that products liabilty lawyers, go away.
