I drive an '06 X5...recently whenever someone or some thing small sits in that side the seatbelt warning light stays on and then starts to chime even when the seatbelt is buckled. The only way to make it stop is if I pull over...put the car in park then drive again. The warning light still stays on but the chime stops...any thoughts to as what the issue is? Mat Sensor? The airbag light does not stay on. Thanks!