Hyundai does indeed have a reprogram available for this, but the dealer is
very restricted in how they can apply this. In order to do the
reprgramming, the dealer is required to witness a passenger seated
properly in the right front seat and the telltale indicating "passenger
air bag off." If this occurs, the dealer can send the seat bottom to
Hyundai to be reprogrammed. To my knowledge, we've never needed to do
such a reprogramming where I work, but I've heard reports that customers
may be required to sign some sort of document if this reprogramming is
performed. You can view the TSB on this procedure at www.hmaservice.com.
It's TSB# 06-90-010-1. The revised TSB indicates that there is a sticker
that should be placed in the owner's manual.
Most of the cases I've seen where the indicator won't go out involve
people small enough that the air bag may present more of a hazard than not
allowing it to deploy.